Work

N-Heterocyclic Carbene-Catalyzed Enantioselective Mannich Reactions with α-Aryloxyacetaldehydes

Year: 2009

Type: article

Abstract: N-Heterocyclic carbenes (NHCs) catalyze a new Mannich-type reaction to form beta-amino acid derivatives in high yield and enantioselectivity. The reaction is initiated by the addition of an NHC to an alpha-aryloxyaldehyde followed by elimination of a phenoxide anion which generates an enol/enolate. A Mannich addition to a tosylimine proceeds with excellent control over enantioselectivity. In a new carbene catalysis concept, catalyst regeneration is promoted by return, or rebound, and acylation of the phenoxide group which served as the activating component in the first step of the catalytic cycle. The activated ester products formed in situ are manipulated to form a variety of useful compounds including beta-amino acids, beta-amino amides, and peptides.

Source: Journal of the American Chemical Society

DOI: 10.1021/ja9094044

Authors: Yasufumi Kawanaka, Eric M. Phillips, Karl A. Scheidt

Institutions: Northwestern University, Chemistry of Life Processes Institute

Language: English

Topic: N-Heterocyclic Carbenes in Organic and Inorganic Chemistry

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: green

Funders: Amgen, AstraZeneca, National Institute of General Medical Sciences

Awards: G344074598, G682315649