Enantioselective direct α-amination of aldehydes via a photoredox mechanism: A strategy for asymmetric amine fragment coupling
The direct, asymmetric α-amination of aldehydes has been accomplished via a combination of photoredox and organocatalysis. Photon-generated N-centered radicals undergo enantioselective α-addition to catalytically formed chiral enamines to directly produce stable α-amino aldehyde adducts bearing synthetically useful amine substitution patterns. Incorporation of a photolabile group on the amine precursor obviates the need to employ a photoredox catalyst in this transformation. Importantly, this photoinduced transformation allows direct and enantioselective access to α-amino aldehyde products that do not require postreaction manipulation.
Cecere, Giuseppe,Koenig, Christian M.,Alleva, Jennifer L.,MacMillan, David W. C.
p. 11521 - 11524
(2013/09/02)
The first asymmetric synthesis of (1R,1′S)-1-[1′-(benzyloxycarbonyl-methylamino)-2′-phenylethyl] oxirane: A promising building block for the synthesis of peptide mimics
The threo N-methyl oxirane 5 was prepared from (S)-N-methyl phenylalanine by bromoketone reduction or by epoxidation routes. The unexpected stereochemical result of the reduction of bromoketone 7 leading to the threo isomer is discussed.