A process is used for the preparation of 1,3,2-oxazaborolidine compounds.This process prepares compounds of formula (I) or (IA): ##STR00001## in which: R1 is an alkyl or an aryl; and R2, R3, R4 and R5 are especially a hydrogen atom or an alkyl, wherein the following are reacted in two steps: a) a boric precursor compound with an acetal compound to give a boronate compound; and b) the boronate compound with an amino alcohol compound.This process avoids by-products and exhibits a very good stereospecificity.

An in situ or one-pot process for the preparation of the compounds of formula (I) uses a compound of general formula (I): ##STR00001## and includes:a) the hydrogenation of a nitrile group of the compound of general formula (II): ##STR00002## in which R.sub.1 to R4 are especially H or alkyl and n varies from 0 to 4, in the presence of a hydrogenation catalyst, a methylating agent and an organic acid as solvent, and at a temperature Ta below the initiation temperature of a reductive amination reaction, to give a primary amine from the nitrile group; andb) the reductive amination of the primary amine in the presence of hydrogen, at a temperature Tb above Ta, to give the dimethylated amine of general formula (I) by activation of the methylating age.

A process for the preparation of optically active substituted alpha-amino-indane derivatives of formula (I), which include: an asymmetric hydrogenation reaction of an en-amide derivative of formula (III) in presence of hydrogen and an optically active catalyst, in order to obtain an amide derivative of formula (II), a hydrolysis reaction of the amide derivative of formula (II) obtained in the previous step,in order to obtain optically active substituted alpha-amino-indane derivatives of formula (I).