A Stereoselective Oxy-Michael Route to Protected β-Aryl-β-Hydroxy-α-Amino Acids

Abstract

A Stereoselective Oxy-Michael Route to Protected b-Aryl-b-Hydroxy-a-Amino Acids R o u t e t o P r o t e c t e d b -A r y l -b -H y d r o x y -a -A m i n o A c i d sAbstract: The stereoselective oxy-Michael addition of the 'naked' anion of (S)-6-methyl tetrahydropyran-2-ol to a-nitro-a,b-unsaturated esters followed by reduction and in situ protection of the corresponding amine provides a new and efficient route to protected baryl-b-hydroxy-a-amino acids.

Rhodium-Catalyzed Double Hydroboration of Quinolines

“…Regioselective reduction of heteroatom-containing conjugated systems, particularly α,β-unsaturated carbonyls, has long been a useful tool for the introduction of functional groups via conjugate nucleophile transfer into a specific position (generally β-position) of the substrates . A range of metal- or metal-free catalytic systems have been documented for enantioselective conjugate additions of water surrogates (alcohols and oximes) and of oxygen equivalents (silicon and boron) to the α,β-unsaturated acceptors. Among the enantioenriched C–X bonds incorporated, the C­(sp 3 )–B bond is known to have good stability and versatile reactivity to be transformed to a broad range of functional groups such as alcohols, amines, and halides, with complete retention of configuration even in late-stage functionalizations …”