Stereoselective sodium borohydride reduction, catalyzed by manganese(II) chloride, of γ-oxo-α-amino acids. A practical approach to syn-γ-hydroxy-α-amino acids

Crystallization-induced asymmetric transformations (CIAT): stereoconvergent acid-catalyzed lactonization of substituted 2-amino-4-aryl-4-hydroxybutanoic acids

“…20,21 We have developed the highly diastereoselective catalytic reduction of N-alkyl substituted aroylalanines 2 leading to the corresponding syn-c-aryl-c-hydroxy-aamino acids. 22 The stereoselectivity of the reduction can be interpreted in terms of chelate formation with a manganese(II) salt, followed by an axial attack of the hydride on the half-chair transition state, which favors the formation of a chair conformation (Fig. 1).…”

Structural analysis of some bis-(8-isopropyl-isoquinolinium) derivatives reveals a preferential folded conformation leading to a stereoselective attack by sodium borohydride

“…This is an original evolution of this reaction involving this small reductive agent. Stereoselective reduction using sodium borohydride is also reported in the literature but additional reagents are mostly added [17,18]. Otherwise, the conformational analysis of other isopropyl analogues with a butyl, a pentyl and a p-xylyl linker discloses extended conformations ( Fig.…”

Sodium Borohydride - A Versatile Reducing Agent

“…10 In most reported cases, the dr is higher than 97:3. (E) A practical procedure for the catalytic reduction of nitriles to Boc amines 12a has been developed; it is neither air-nor moisturesensitive, and is easily worked up.…”