TY - JOUR
T1 - Phosphine-Catalyzed Enantioselective Intramolecular [3+2] Annulations to Generate Fused Ring Systems
AU - Lee, Sarah Yunmi
AU - Fujiwara, Yuji
AU - Nishiguchi, Atsuko
AU - Kalek, Marcin
AU - Fu, Gregory C.
N1 - Publisher Copyright:
© 2015 American Chemical Society.
Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2015/3/27
Y1 - 2015/3/27
N2 - Substantial progress has been described in the development of asymmetric variants of the phosphine-catalyzed intermolecular [3+2] annulation of allenes with alkenes; however, there have not been corresponding advances for the intramolecular process, which can generate a higher level of complexity (an additional ring and stereocenter(s)). In this study, we describe the application of chiral phosphepine catalysts to address this challenge, thereby providing access to useful scaffolds that are found in bioactive compounds, including diquinane and quinolin-2-one derivatives, with very good stereoselectivity. The products of the [3+2] annulation can be readily transformed into structures that are even more stereochemically rich. Mechanistic studies are consistent with β addition of the phosphepine to the allene being the turnover-limiting step of the catalytic cycle, followed by a concerted [3+2] cycloaddition to the pendant olefin. (Chemical Equation Presented)
AB - Substantial progress has been described in the development of asymmetric variants of the phosphine-catalyzed intermolecular [3+2] annulation of allenes with alkenes; however, there have not been corresponding advances for the intramolecular process, which can generate a higher level of complexity (an additional ring and stereocenter(s)). In this study, we describe the application of chiral phosphepine catalysts to address this challenge, thereby providing access to useful scaffolds that are found in bioactive compounds, including diquinane and quinolin-2-one derivatives, with very good stereoselectivity. The products of the [3+2] annulation can be readily transformed into structures that are even more stereochemically rich. Mechanistic studies are consistent with β addition of the phosphepine to the allene being the turnover-limiting step of the catalytic cycle, followed by a concerted [3+2] cycloaddition to the pendant olefin. (Chemical Equation Presented)
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U2 - 10.1021/jacs.5b01985
DO - 10.1021/jacs.5b01985
M3 - Article
C2 - 25815702
AN - SCOPUS:84926644385
VL - 137
SP - 4587
EP - 4591
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 13
ER -