Benzotriazole-Mediated Stereoselective Olefination of Carboxylic Esters: Transformation of α-Amino Acid Esters into Chiral Allylamines

Article abstract of DOI:10.1021/jo971546f

Diastereoselective trans-olefinations of carboxylic esters 3a-h have been accomplished using benzylic or allylic benzotriazole derivatives 1a-e to prepare α-(benzotriazol-1-yl) ketones 4a-i, for the subsequent reduction of 4a-i, and finally for low-valent titanium-effected dehydroxybenzotriazolylation.¹ N-Protected α-amino acid esters 9a-c and 15 thus give allylamines 13a-e and 19 with virtually full retention of chirality. Mechanistic aspects of the dehydroxybenzotriazolylation are discussed.