Publicaciones

Esta sección incluye una lista de los últimos artículos científicos del IPNA publicados en revistas incluidas en el Science Citation Index (SCI).

En DIGITAL.CSIC, repositorio institucional del CSIC, pueden encontrar el listado completo de artículos científicos desde 1962, así como otras colecciones de interés como congresos, tesis, libros, material divulgativo, etc. del centro. El objetivo de DIGITAL.CSIC es organizar, preservar y difundir en acceso abierto los resultados de nuestra investigación.

En el repositorio institucional del CSIC, pueden encontrar el listado completo de artículos científicos, así como otras colecciones de interés como congresos, tesis, libros, material divulgativo, etc.

Ir a Digital - CSIC

 

Análisis de la Producción Científica del IPNA 2014-2019: análisis bibliométrico realizado a partir de datos recogidos en Scopus y Web of Science.

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Digital CSIC
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Dust and tropical PMx aerosols in Cape Verde: Sources, vertical distributions and stratified transport from North Africa

Dust and tropical PMx aerosols in Cape Verde: Sources, vertical distributions and stratified transport from North Africa

We investigated the sources and processes affecting the vertical distribution of tropical PMx aerosols (particulate matter -PM- smaller than 10, 2.5 and 1 μm, PM10, PM2.5 and PM1, respectively) in the low troposphere of Santo Antão and São Vicente islands, in Cape Verde archipelago, a region where a better understanding of aerosols is needed due to their involvement in tropical meteorology and their impact on air quality, ocean and climate. We found that local sources had a low-scale impact. From transect measurements at ground level, we found that PMx levels were predominantly low, except near to PMx sources, where distinctive PM1 / PM2.5 ratios were measured, linked to vehicle exhaust (0.96), biomass burning (0.67) and Cape Verdean dust (0.36) emissions. The depth of the marine boundary layer (MBL) and the vertical distributions of PMx showed wide variability prompted by meteorological conditions. The trade winds prevailed in the MBL, whereas other airflows were situated above it: North-Atlantic, African easterly airflow and Saharan Air Layer. Under North-Atlantic airflow conditions, the MBL extended to 1400 m above sea level (m.a.s.l.). Above this altitude, PMx concentrations decreased quickly (< 3 μg/m3) due to the free troposphere conditions. Under Saharan dust conditions, the MBL was confined to just 70 m.a.s.l., whereas a complex dust stratification was observed above, characterized by alternating dry air layers with high dust loads (PM10 ~ 100 μg/m3) and more humid air layers with lower aerosol loads (PM10 ~ 40 μg/m3). Within the dry easterly African airflow occurring above the marine stratocumulus typical of the MBL top (placed at 500 m.a.s.l.), we detected layers enriched in hydrophilic aerosols (PM10: ~ 8 μg/m3). These were imbedded in relatively humid air (RH ~48%), probably linked to secondary aerosol formation by in-cloud processes in the marine stratocumulus situated below. We found that PMx transport from North Africa, both under dust and dust-free conditions, is associated with complex vertical stratifications, even within the dusty Saharan Air Layer.

Rodríguez, Sergio; López-Darias, Jessica

Atmospheric Research 263: 105793 (2021)
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Litosetoenins A–E, Diterpenoids from the Soft Coral Litophyton setoensis, Backbone-Rearranged through Divergent Cyclization Achieved by Epoxide Reactivity Inversion

Litosetoenins A–E, Diterpenoids from the Soft Coral Litophyton setoensis, Backbone-Rearranged through Divergent Cyclization Achieved by Epoxide Reactivity Inversion

Litosetoenins A–E (1–5), five new ring-rearranged serrulatane-type diterpenoids with a common tricyclo[3.0.4]decane core, along with a known diterpenoid glycoside (6), a related known diterpenoid (7), and four known sesquiterpenoids (8–11), were isolated from a Balinese soft coral Litophyton setoensis. Spirolitosetoenin A (5a) and isospirolitosetoenin A (5b), featuring an unprecedented spiro[4,5]decane core, were obtained after treatment of compound 5 with HCl in methanol. The structures of new compounds were elucidated by extensive spectroscopic analysis, quantum mechanical nuclear magnetic resonance approach, and chemical methods. A plausible biosynthetic pathway involving an unusual divergent biogenesis was proposed.

Li, Song-Wei; Mudianta, I. Wayan; Cuadrado, Cristina; Geng, Li; Yudasmara, Gede A.; Setiabudi, Gede I. ;Hernández Daranas, Antonio; Guo, Yue-Wei

Journal of Organic Chemistry 86(17): 11771–11781 (2021)
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A unified model of species abundance, genetic diversity, and functional diversity reveals the mechanisms structuring ecological communities

A unified model of species abundance, genetic diversity, and functional diversity reveals the mechanisms structuring ecological communities

Biodiversity accumulates hierarchically by means of ecological and evolutionary processes and feedbacks. Within ecological communities drift, dispersal, speciation, and selection operate simultaneously to shape patterns of biodiversity. Reconciling the relative importance of these is hindered by current models and inference methods, which tend to focus on a subset of processes and their resulting predictions. Here we introduce Massive Eco-evolutionary Synthesis Simulations (MESS), a unified mechanistic model of community assembly, rooted in classic island biogeography theory, which makes temporally explicit joint predictions across three biodiversity data axes: i) species richness and abundances; ii) population genetic diversities; and iii) trait variation in a phylogenetic context. Using simulations we demonstrate that each data axis captures information at different timescales, and that integrating these axes enables discriminating among previously unidentifiable community assembly models. MESS is unique in generating predictions of community-scale genetic diversity, and in characterizing joint patterns of genetic diversity, abundance, and trait values. MESS unlocks the full potential for investigation of biodiversity processes using multi-dimensional community data including a genetic component, such as might be produced by contemporary eDNA or metabarcoding studies. We combine with supervised machine learning to fit the parameters of the model to real data and infer processes underlying how biodiversity accumulates, using communities of tropical trees, arthropods, and gastropods as case studies that span a range of data availability scenarios, and spatial and taxonomic scales.

Overcast, Isaac; Ruffley, Megan; Rosindell, James; Harmon, Luke ; Borges, Paulo A. V.; Emerson, Brent C.; Etienne, Rampal S.; Gillespie, Rosemary; Krehenwinkel, Henrik; Mahler, D. Luke; Massol, Francois; Parent, Christine E.; Patiño, Jairo; Peter, Ben; Week, Bob; Wagner, Catherine; Hickerson, Michael J.; Rominger, Andrew

Molecular Ecology Resources: 1-46 (2021)
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Macroclimatic structuring of spatial phylogenetic turnover in liverworts

Macroclimatic structuring of spatial phylogenetic turnover in liverworts

Phylogenetic turnover has emerged as a powerful tool to identify the mechanisms by which biological communities assemble. When significantly structured along environmental gradients, phylogenetic turnover evidences phylogenetic niche conservatism, a critical principle explaining patterns of species distributions at different spatio–temporal scales. Here, we quantify the contribution of geographic and macroclimatic drivers to explain patterns of phylogenetic turnover in an entire phylum of land plants, namely liverworts. We further determine whether climatic niche conservatism has constrained the distribution of liverworts in the course of their evolutionary history. Two datasets, one insular, focused on 60 archipelagos and including 2346 species, and the second global, including 6334 species in 451 oceanic and continental operational geographic units (OGUs) worldwide, were assembled. Phylogenetic turnover among OGUs was quantified through πst statistics. πst-through-time profiles were generated at 1 Myr intervals along the phylogenetic time-scale and used to compute the correlation between πst, current geographic distance and macroclimatic variation with Mantel tests based on Moran spectral randomization to control for spatial autocorrelation. The contribution of macroclimatic variation to phylogenetic turnover was about four-times higher than that of geographic distance, a pattern that was consistently observed in island and global geographic settings, and with datasets including or excluding species-poor OGUs. The correlation between phylogenetic turnover and geographic distance rapidly decayed at increasing phylogenetic depth, whereas the relationship with macroclimatic variation remained constant until 100 Mya. Our analyses reveal that changes in the phylogenetic composition among liverwort floras across the globe are primarily shaped by macroclimatic variation. They demonstrate the relevance of macroclimatic niche conservatism for the assembly of liverwort floras over very large spatial and evolutionary time scales, which may explain why such a pervasive biodiversity pattern as the increase of species richness towards the tropics also applies to organisms with high dispersal capacities.

Collart, Flavien; Wang, Jian ;Patiño, Jairo; Hagborg, Anders; Söderström, Lars; Goffinet, Bernard; Magain, Nicolas; Hardy, Olivier J.; Vanderpoorten, Alain

Ecography: 1-12 (2021)
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Trophic strategies of two sympatric endemic pigeons in insular ecosystems: a framework for understanding spatiotemporal frugivory interactions

Trophic strategies of two sympatric endemic pigeons in insular ecosystems: a framework for understanding spatiotemporal frugivory interactions

Pigeons are considered to play key ecological roles in frugivory and seed dispersal. They have colonised numerous oceanic islands and diversified into several species in sympatry. How these species coexist in similar niches is poorly understood although dietary separation is among the mechanisms suggested to avoid trophic overlap. We investigated the trophic ecology of the two endemic Columba species co-occurring in the laurel forest and thermosclerophyllous relicts of two of the Canary Islands. This study includes diet description in spatiotemporal terms, its relationship with fruit availability and seed treatment in 10 study areas established on La Palma and La Gomera. We used non-invasive DNA analysis to identify the faeces of the two con-generic species and microhistological methods to examine their diets. The degree of trophic overlap was evaluated by niche similarity and breadth indices. Molecular faecal sampling determined the spatiotemporal distribution of both pigeons to identify their areas of coexistence. These frugivorous pigeons’ diets did not differ concerning the main plant species, but they diverged quantitatively in the proportions and parts of plants consumed. Lauraceae fruits were their staple foods although Rhamnaceae and some Fabaceae and Solanaceae were also important. Both pigeons showed selective preferences for some fruits. Significant spatiotemporal variations in their diets were observed along with a general tendency to increase fruit intake at its ripening times. Our results suggest that different trophic strategies facilitate the coexistence of these frugivorous columbids. These pigeons act as seed dispersers and/or predators depend ing on seed features (size and hardness), and this may have valuable implications for their conservation.

Marrero, Patricia; Nogales, Manuel 

Journal of Avian Biology: 1-14 (2021)
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Coming of age for COI metabarcoding of whole organism community DNA: towards bioinformatic harmonisation

Coming of age for COI metabarcoding of whole organism community DNA: towards bioinformatic harmonisation

Metabarcoding of DNA extracted from community samples of whole organisms (whole organism community DNA, wocDNA) is increasingly being applied to terrestrial, marine and freshwater metazoan communities to provide rapid, accurate and high resolution data for novel molecular ecology research. The growth of this field has been accompanied by considerable development that builds on microbial metabarcoding methods to develop appropriate and efficient sampling and laboratory protocols for whole organism metazoan communities. However, considerably less attention has focused on ensuring bioinformatic methods are adapted and applied comprehensively in wocDNA metabarcoding. In this study we examined over 600 papers and identified 111 studies that performed COI metabarcoding of wocDNA. We then systematically reviewed the bioinformatic methods employed by these papers to identify the state-of-the-art. Our results show that the increasing use of wocDNA COI metabarcoding for metazoan diversity is characterised by a clear absence of bioinformatic harmonisation, and the temporal trends show little change in this situation. The reviewed literature showed (i) high heterogeneity across pipelines, tasks and tools used, (ii) limited or no adaptation of bioinformatic procedures to the nature of the COI fragment, and (iii) a worrying underreporting of tasks, software and parameters. Based upon these findings we propose a set of recommendations that we think the wocDNA metabarcoding community should consider to ensure that bioinformatic methods are appropriate, comprehensive and comparable. We believe that adhering to these recommendations will improve the long-term integrative potential of wocDNA COI metabarcoding for biodiversity science.

Creedy, Thomas; Andújar, Carmelo; Noguerales, Víctor; Overcast, Isaac; Papadopoulou, Anna; Morlon, Hélène; Vogler, Alfried; Emerson, Brent C.; Arribas, Paula 

Molecular Ecology Resources 1-30 (2021)

Sea dispersal potential and colonization of the Galápagos littoral flora

Aim Seed dispersal by oceanic currents (thalassochory) is considered one of the main long-distance dispersal (LDD) mechanisms for the colonization of oceanic islands by plants. Diaspores of littoral species are often hypothesized to be physiologically adapted to seawater dispersal, favouring interisland colonization. In this study, we experimentally tested the sea dispersal potential of a large proportion of Galápagos littoral flora and explored its correlation with plant distribution across the archipelago. We propose a simple Sea Dispersal Potential index (SDPi) to quantify the thalassochorous potential of any species. Location Galápagos archipelago. Taxon Littoral angiosperms. Methods We combined information on seed floatability (flotation time) and viability experiments (tetrazolium test) into an SDPi for 19 native littoral plants and tested whether increasing dispersal potential is associated with broader interisland distributions. We then tested if the presence of morphological structures related to thalassochory is associated with the functional SDPi. Results A relatively low, albeit highly variable, SDPi across Galápagos littoral plant species was found. No correlation was found between SDPi and species distributions. Morphological traits hypothesized to favour sea dispersal are not related to thalassorous potentials to reach closest islands, but they are positively associated with SDPi to reach the farthest islands. Main conclusions SDPi is shown to be a useful tool to compare the thalassochorous potentials of entire floras in a given geographical context. The low performance of most of the species questions the general assumption that most littoral plants are highly adapted to long-distance sea dispersal. Our results support the view that island colonization is a multifactorial process and that the use of dispersal syndromes is insufficient to make biogeographical predictions in macroecology studies. Further research should integrate functional indices (e.g., SDPi) with complementary tools (genetics, remote diaspore tracking) to determine the actual drivers of species dispersal and establishment.

Fuster-Calvo, Alexandre; Nogales, Manuel; Heleno, Rubén; Vera, Carlos; Vargas, Pablo

Journal of Biogeography 48(8): 1904-1916 (2021)
DOIDigital.CSIC

Validation of a Method Scope Extension for the Analysis of POPs in Soil and Verification in Organic and Conventional Farms of the Canary Islands

Persistent organic pollutants (POPs) are among the most relevant and dangerous contaminants in soil, from where they can be transferred to crops. Additionally, livestock animals may inadvertently consume relatively high amounts of soil attached to the roots of the vegetables while grazing, leading to indirect exposure to humans. Therefore, periodic monitoring of soils is crucial; thus, simple, robust, and powerful methods are needed. In this study, we have tested and validated an easy QuEChERS-based method for the extraction of 49 POPs (8 PBDEs, 12 OCPs, 11 PAHs, and 18 PCBs) in soils and their analysis by GC-MS/MS. The method was validated in terms of linearity, precision, and accuracy, and a matrix effect study was performed. The limits of detection (LOD) were established between 0.048 and 3.125 ng g−1 and the limits of quantification (LOQ) were between 0.5 and 20 ng g−1, except for naphthalene (50 ng g−1). Then, to verify the applicability of the validated method, we applied it to a series of 81 soil samples from farms dedicated to mixed vegetable cultivation and vineyards in the Canary Islands, both from two modes of production (organic vs. conventional) where residues of OCPs, PCBs, and PAHs were found.

Acosta-Dacal, Andrea; Rial-Berriel, Cristina; Díaz-Díaz, Ricardo; Bernal-Suárez, María del Mar; Zumbado, Manuel; Henríquez-Hernández, Luis Alberto; Alonso-González, Pablo ; Parga-Dans, Eva ; Luzardo, Octavio P.

Toxics 9(5), 101: 1-17 (2021)
DOIDigital.CSIC

Short and Modular Synthesis of Substituted 2-Aminopyrroles

We herein describe a simple and metal-free domino methodology to synthesize 2-aminopyrroles from alkynyl vinyl hydrazides. The domino reaction involves a novel propargylic 3,4-diaza-Cope rearrangement and a tandem isomerization/5-exo-dig N-cyclization reaction. By using this approach, a number of 2-aminopyrroles with diverse substituents have been prepared.

Diana-Rivero, Raquel; Halsvik, Beate; García-Tellado, Fernando; Tejedor, David

Organic Letters 23(10): 4078–4082 (2021)
DOIDigital.CSIC

Sesquiterpene Lactones from Artemisia absinthium. Biotransformation and Rearrangement of the Insect Antifeedant 3α-hydroxypelenolide

Three new compounds, the sesquiterpenes absilactone and hansonlactone and the acetophenone derivative ajenjol, have been isolated from a cultivated variety of Artemisia absinthium. In addition, the major lactone isolated, 3α-hydroxypelenolide, was biotransformed by the fungus Mucor plumbeus affording the corresponding 1β, 10α-epoxide. A cadinane derivative was formed by an acid rearrangement produced in the culture medium, but not by the enzymatic system of the fungus. Furthermore, 3α-hydroxypelenolide showed strong antifeedant effects against Leptinotarsa decemlineata and cytotoxic activity to Sf9 insect cells, while the biotransformed compounds showed antifeedant postingestive effects against Spodoptera littoralis.

Fraga, Braulio M.; Díaz, Carmen E.; Bailén, María; González-Coloma, Azucena

Plants 10(5), 891: 1-14 (2021)
DOIDigital.CSIC

Endogean beetles (Coleoptera) of Madagascar: deep soil sampling and illustrated overview

This study addresses the diversity of deep soil beetles on the old continental island of Madagascar. We highlight Coleoptera as the only order of insects repeatedly occupying the deep soil (=endogean) habitat. We describe and illustrate soil flotation technique used during our fieldwork in Madagascar in December 2019. We focus on the method’s high-output and mobile technicalities. We document 51 deep soil samples, each about 20 litres in volume, taken by us in varying Malagasy localities (Andringitra, Road RN7, Ankaratra, Andasibe) and habitats (primary forest versus grassland). We provide a preliminary illustrated overview of 1,430 deep soil beetles of Madagascar sampled by us. They include representatives of Carabidae (Anillini, Reicheiina), Leiodidae, Staphylinidae (Aleocharinae, Euaesthetinae, Osoriinae, Paederinae, Pselaphinae, Scydmaeninae), Scarabaeidae, Tenebrionidae and Curculionidae. We emphasize the significant disparity between collecting 1,430 adult endogean beetles and only about a dozen of their larvae, all belonging to Scydmaeninae.

Andújar, Carmelo; Grebennikov, Vasily V.

Zootaxa 4963(2): 317-334 (2021)
DOIDigital.CSIC

Coumarins and other constituents from Deverra battandieri

Three undescribed coumarin derivatives, pituranthosin A–C (1-3), along with nineteen known compounds were isolated and identified from the chloroform and ethyl acetate fractions of the hydroalcoholic extract of Deverra battandieri (Apiaceae). The structures of the compounds were established by interpretation of their spectral data using 1D-NMR (1H, 13C, DEPT experiments), 2D-NMR (COSY, NOESY, HSQC and HMBC), HRESIMS, and by comparison with the literature data.

Esseid, Chahrazed; León, Francisco; Mosset, Paul; Benayache, Samir; Marchioni, Eric; Brouard, Ignacio; Benayache, Fadila

Phytochemistry Letters 42: 129-133 (2021)
DOIDigital.CSIC

Digest: Parallel rather than unique local adaptation along a steep elevation gradient

To what extent do parallel and unique local adaptation occur along elevational gradients? In a reciprocal transplant experiment, Bachmann and Van Buskirk found stronger evidence for parallel adaptation to elevation than for unique local adaptation in Rana temporaria populations of the Swiss Alps. This finding has important implications for understanding gene flow effects on adaptive patterns and provides a useful investigative framework for the study of adaptation.

Arjona, Yurena; Morente-López, Javier

Evolution 75(4): 972-974 (2021)
DOIDigital.CSIC

Bioinformatic Analysis of Genome-Predicted Bat Cathelicidins

Bats are unique in their potential to serve as reservoir hosts for intracellular pathogens. Recently, the impact of COVID-19 has relegated bats from biomedical darkness to the frontline of public health as bats are the natural reservoir of many viruses, including SARS-Cov-2. Many bat genomes have been sequenced recently, and sequences coding for antimicrobial peptides are available in the public databases. Here we provide a structural analysis of genome-predicted bat cathelicidins as components of their innate immunity. A total of 32 unique protein sequences were retrieved from the NCBI database. Interestingly, some bat species contained more than one cathelicidin. We examined the conserved cysteines within the cathelin-like domain and the peptide portion of each sequence and revealed phylogenetic relationships and structural dissimilarities. The antibacterial, antifungal, and antiviral activity of peptides was examined using bioinformatic tools. The peptides were modeled and subjected to docking analysis with the region binding domain (RBD) region of the SARS-CoV-2 Spike protein. The appearance of multiple forms of cathelicidins verifies the complex microbial challenges encountered by these species. Learning more about antiviral defenses of bats and how they drive virus evolution will help scientists to investigate the function of antimicrobial peptides in these species.

Pérez de Lastra, José Manuel; Asensio-Calavia, Patricia; González-Acosta, Sergio; Baca-González, Victoria; Morales-de la Nuez, Antonio

Molecules 26(6), 1181: 1-16 (2021)
DOIDigital.CSIC

The Essentials of Marine Biotechnology

Coastal countries have traditionally relied on the existing marine resources (e.g., fishing, food, transport, recreation, and tourism) as well as tried to support new economic endeavors (ocean energy, desalination for water supply, and seabed mining). Modern societies and lifestyle resulted in an increased demand for dietary diversity, better health and well-being, new biomedicines, natural cosmeceuticals, environmental conservation, and sustainable energy sources. These societal needs stimulated the interest of researchers on the diverse and underexplored marine environments as promising and sustainable sources of biomolecules and biomass, and they are addressed by the emerging field of marine (blue) biotechnology. Blue biotechnology provides opportunities for a wide range of initiatives of commercial interest for the pharmaceutical, biomedical, cosmetic, nutraceutical, food, feed, agricultural, and related industries. This article synthesizes the essence, opportunities, responsibilities, and challenges encountered in marine biotechnology and outlines the attainment and valorization of directly derived or bio-inspired products from marine organisms. First, the concept of bioeconomy is introduced. Then, the diversity of marine bioresources including an overview of the most prominent marine organisms and their potential for biotechnological uses are described. This is followed by introducing methodologies for exploration of these resources and the main use case scenarios in energy, food and feed, agronomy, bioremediation and climate change, cosmeceuticals, bio-inspired materials, healthcare, and well-being sectors. The key aspects in the fields of legislation and funding are provided, with the emphasis on the importance of communication and stakeholder engagement at all levels of biotechnology development. Finally, vital overarching concepts, such as the quadruple helix and Responsible Research and Innovation principle are highlighted as important to follow within the marine biotechnology field. The authors of this review are collaborating under the European Commission-funded Cooperation in Science and Technology (COST) Action Ocean4Biotech – European transdisciplinary networking platform for marine biotechnology and focus the study on the European state of affairs.

Rotter, Ana; Barbier, Michéle; Bertoni, Franceso; Bones, Atle M.; Cancela, M. Leonor; Carlsson, Jens; Carvalho, Maria F.; Cegłowska, Marta; Chirivella-Martorell, Jerónimo; Conk Dalay, Meltem; Cueto, Mercedes; Dailianis, Thanos; Deniz, Irem; Díaz-Marrero, Ana R.; Drakulovic, Dragana; Dubnika, Arita; Edwards, Christine; Einarsson, Hjörleifur; Erdogan, Aysegül; Eroldogan, Orhan Tufan; Ezra, David; Fazi, Stefano; FitzGerald, Richard J.; Gargan, Laura M.; Gaudêncio, Susana P.; Gligora Udovic, Marija; Ivoševic DeNardis, Nadica; Jónsdóttir, Rósa; Kataržyte, Marija; Klun, Katja; Kotta, Jonne; Ktari, Leila; Ljubešic, Zrinka; Lukic Bilela, Lada; Mandalakis, Manolis; Massa-Gallucci, Alexia; Matijošyte, Inga; Mazur-Marzec, Hanna; Mehiri, Mohamed; Laurentius Nielsen, Søren; Novoveská, Lucie; Overlingé, Donata; Perale, Guiseppe; Ramasamy, Praveen; Rebours, Céline; Reinsch, Thorsten; Reyes, Fernando; Rinkevich, Baruch; Robbens, Johan; Röttinger, Eric; Rudovica, Vita; Sabotic, Jerica; Safarik, Ivo; Talve, Siret; Tasdemir, Deniz; Theodotou Schneider, Xenia; Thomas, Olivier P.; Torunska-Sitarz, Anna; Varese, Giovanna Cristina; Vasquez, Marlen I.

Marine Biotechnology 16, 629629: 1-53 (2021)
DOIDigital.CSIC

Intramolecular Nicholas Reaction Enables the Stereoselective Synthesis of Strained Cyclooctynes

Cyclic products can be obtained through the intramolecular version of the Nicholas reaction, which requires having the nucleophile connected to the alkyne unit. Here, we report the synthesis of 1-oxa-3-cyclooctynes starting from commercially available (1R,3S)-camphoric acid. The strategy is based on the initial preparation of propargylic alcohols, complexation of the triple bond with Co2(CO)8, and treatment with BF3·Et2O to induce an intramolecular Nicholas reaction with the free hydroxyl group as nucleophile. Finally, oxidative deprotection of the alkyne afforded the cyclooctynes in good yields. Notably, large-sized R substituents at the chiral center connected to the O atom were oriented in such a way that steric interactions were minimized in the cyclization, allowing the formation of cyclooctynes exclusively with (R) configuration, in good agreement with theoretical predictions. Moreover, preliminary studies demonstrated that these cyclooctynes were reactive in the presence of azides yielding substituted triazoles.

Monzón, Diego M.; Betancort, Juan Manuel; Martín, Tomás ; Ramírez, Miguel Ángel; Martín, Víctor S.; Díaz Díaz, David

Molecules 26(6), 1629: 1-12 (2021)
DOIDigital.CSIC