A convenient synthesis of new diamine, aminoalcohol and aminophosphines chiral auxiliaries based on limonene oxide

A strategy for the synthesis of new chiral auxiliaries based upon vicinal diamines, amino alcohols and aminophosphines, obtained from limonene oxide, has been developed. The methodology allows the preparation of (1R,2R,4S)-1-methyl-4-(prop-1-en-2-yl)cyclohexane-1,2-diamine starting from a commercially available mixture of cis/trans (4S)-(-)-limonene oxides, through a stereoconvergent synthetic sequence. The process starts from an inexpensive naturally occurring material, is amenable to scale-up and allows easy access to highly useful enantiopure building blocks and ligands, employed in asymmetric catalysis.