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Oxy-Allyl Cation Catalysis: An Enantioselective Electrophilic Activation Mode.

ABSTRACT: A generic activation mode for asymmetric LUMO-lowering catalysis has been developed using the long-established principles of oxy-allyl cation chemistry. Here, the enantioselective conversion of racemic ?-tosyloxy ketones to optically enriched ?-indolic carbonyls has been accomplished using a new amino alcohol catalyst in the presence of electron-rich indole nucleophiles. Kinetic studies reveal that the rate-determining step in this S(N)1 pathway is the catalyst-mediated ?-tosyloxy ketone deprotonation step to form an enantiodiscriminant oxy-allyl cation prior to the stereodefining nucleophilic addition event.

SUBMITTER: Liu C

PROVIDER: S-EPMC5103282 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature

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Oxy-Allyl Cation Catalysis: An Enantioselective Electrophilic Activation Mode.

Liu Chun C Oblak E Zachary EZ Vander Wal Mark N MN Dilger Andrew K AK Almstead Danielle K DK MacMillan David W C DW

Journal of the American Chemical Society 20160209 7

A generic activation mode for asymmetric LUMO-lowering catalysis has been developed using the long-established principles of oxy-allyl cation chemistry. Here, the enantioselective conversion of racemic α-tosyloxy ketones to optically enriched α-indolic carbonyls has been accomplished using a new amino alcohol catalyst in the presence of electron-rich indole nucleophiles. Kinetic studies reveal that the rate-determining step in this S(N)1 pathway is the catalyst-mediated α-tosyloxy ketone deproto ...[more]

PMID: 26797012

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