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Tandem catalytic enantio‐ and diastereoselective synthesis of cyclopropyl alcohols using aryl aldehydes
Author(s) -
Kim Hun Young,
Walsh Patrick J.
Publication year - 2012
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.2965
Subject(s) - chemistry , aldehyde , aryl , enantioselective synthesis , tandem , diastereomer , allylic rearrangement , catalysis , stereoselectivity , reagent , organic chemistry , yield (engineering) , combinatorial chemistry , alkyl , materials science , metallurgy , composite material
The prevalence of cyclopropanes in biologically active compounds has fueled many investigations into their preparation. Despite significant advances, more efficient methods for their catalytic enantioselective synthesis remain in demand. Previously, we reported a novel tandem approach to diastereo‐ and enantioenriched cyclopropyl alcohols. Our method involved an initial asymmetric C–C bond formation by addition of organozinc reagents to aldehydes catalyzed by a (−)‐MIB‐based catalyst. The resulting allylic zinc alkoxides were then subject to directed cyclopropanations . Although this approach provided cyclopropyl alcohols with very high enantio‐ and diastereoselectivity, it was successful with only aliphatic aldehydes. Aryl aldehyde substrates, on the other hand, exhibited low conversion and variable diastereomeric ratios. The present study is aimed at raising the stereoselectivity and yield of the aforementioned tandem reaction with aryl aldehyde substrates to make the method synthetically useful. Herein, we report the successful optimization of aryl aldehyde substrates in our one‐pot tandem approach leading to cyclopropyl alcohols with high yields and enantio‐ and diastereoselectivities. Copyright © 2012 John Wiley & Sons, Ltd.