Synthesis of BINOL derived phosphorodithioic acids as new chiral Brønsted acids and an improved synthesis of 3,3′-disubstituted H8-BINOL derivatives

Original phosphorodithioic acid diesters were prepared according to an improved synthesis of 3,3′-disubstituted H8-BINOL derivatives. In preliminary experiments, these new Brønsted acids were tested as organocatalysts in three reactions. They promoted the Nazarov cyclisation with mixed selectivities, the Mannich reaction with good enantioselectivity and they catalyzed efficiently the alkylation of N-acyliminium with enol silyl ether.