Chiral aminoalcohol NOBIN for instantaneous chirality control of racemic but tropos BIPHEP-Rh(I)-complexes: highly enantioselective ene-type cyclization of 1,6-enynes catalyzed by the Rh(I)-complexes without use of acid

The tropos (chirally flexible) or atropos (chirally rigid) nature of BIPHEP-Rh complexes critically depends on amines and alcohols complexed. The BIPHEP-Rh complex with aminoalcohol NOBIN is significantly tropos and can be chirally controlled by aminoalcohol NOBIN instantaneously even at room temperature. The BIPHEP-Rh/NOBIN complex thus controlled can be used as an asymmetric catalyst to give higher enantioselectivity (up to 98% ee) and yield in ene-type cyclization of 1,6-enynes without use of acid.