Boric ester synthesis

摘要

Stable alpha -substituted boronic esters, e.g. for use in peptide synthesis, are prepared by reacting a substituted alkene of the formula: <IMAGE> with a disubstituted borane of the formula: <IMAGE> wherein: (i) R1 and R2 are each selected from various groups which are preferably not leaving groups; (ii) X is halogen or other leaving group; (iii) Y is H or lower alkyl; (iv) Q1 and Q2 are each selected from various groups which are preferably such that the borane is non-hydrolyzable, and particularly Q1 and Q2 together may represent a residue of a diol such as catechol or pinanediol.