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Boron Carboxylate Catalysis of Homoallylboration

[Image: see text] Boron tris(trifluoroacetate) is identified as the first effective catalyst for the homoallyl- and homocrotylboration of aldehydes by cyclopropylcarbinylboronates. NMR spectroscopic studies and theoretical calculations of key intermediates and transition states both suggest that a l...

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Autores principales: Dugas, Gabrielle J., Lam, Yu-hong, Houk, K. N., Krauss, Isaac J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2014
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4033657/
https://www.ncbi.nlm.nih.gov/pubmed/24754566
http://dx.doi.org/10.1021/jo500599h
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author Dugas, Gabrielle J.
Lam, Yu-hong
Houk, K. N.
Krauss, Isaac J.
author_facet Dugas, Gabrielle J.
Lam, Yu-hong
Houk, K. N.
Krauss, Isaac J.
author_sort Dugas, Gabrielle J.
collection PubMed
description [Image: see text] Boron tris(trifluoroacetate) is identified as the first effective catalyst for the homoallyl- and homocrotylboration of aldehydes by cyclopropylcarbinylboronates. NMR spectroscopic studies and theoretical calculations of key intermediates and transition states both suggest that a ligand-exchange mechanism, akin to our previously reported PhBCl(2)-promoted homoallylations, is operative. Our experimental and theoretical results also suggest that the catalytic activity of boron tris(trifluoroacetate) might originate from more facile catalytic turnover of the trifluoroacetate ligands (in agreement with DFT calculations) or from a lower propensity for formation of off-pathway reservoir intermediates (as observed by (1)H NMR). This work shows that carboxylates are viable catalytic ligands for homoallyl- and homocrotylations of carbonyl compounds and opens the door to the development of catalytic asymmetric versions of this transformation.
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spelling pubmed-40336572015-04-23 Boron Carboxylate Catalysis of Homoallylboration Dugas, Gabrielle J. Lam, Yu-hong Houk, K. N. Krauss, Isaac J. J Org Chem [Image: see text] Boron tris(trifluoroacetate) is identified as the first effective catalyst for the homoallyl- and homocrotylboration of aldehydes by cyclopropylcarbinylboronates. NMR spectroscopic studies and theoretical calculations of key intermediates and transition states both suggest that a ligand-exchange mechanism, akin to our previously reported PhBCl(2)-promoted homoallylations, is operative. Our experimental and theoretical results also suggest that the catalytic activity of boron tris(trifluoroacetate) might originate from more facile catalytic turnover of the trifluoroacetate ligands (in agreement with DFT calculations) or from a lower propensity for formation of off-pathway reservoir intermediates (as observed by (1)H NMR). This work shows that carboxylates are viable catalytic ligands for homoallyl- and homocrotylations of carbonyl compounds and opens the door to the development of catalytic asymmetric versions of this transformation. American Chemical Society 2014-04-23 2014-05-16 /pmc/articles/PMC4033657/ /pubmed/24754566 http://dx.doi.org/10.1021/jo500599h Text en Copyright © 2014 American Chemical Society
spellingShingle Dugas, Gabrielle J.
Lam, Yu-hong
Houk, K. N.
Krauss, Isaac J.
Boron Carboxylate Catalysis of Homoallylboration
title Boron Carboxylate Catalysis of Homoallylboration
title_full Boron Carboxylate Catalysis of Homoallylboration
title_fullStr Boron Carboxylate Catalysis of Homoallylboration
title_full_unstemmed Boron Carboxylate Catalysis of Homoallylboration
title_short Boron Carboxylate Catalysis of Homoallylboration
title_sort boron carboxylate catalysis of homoallylboration
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4033657/
https://www.ncbi.nlm.nih.gov/pubmed/24754566
http://dx.doi.org/10.1021/jo500599h
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