Rhodium-catalyzed double [2+2+2] cycloaddition of 1, 4-bis(diphenylphosphinoyl)buta-1, 3-diyne with tethered diynes: A modular, highly versatile single-pot synthesis of NU-BIPHEP biaryl diphosphines

Rhodium-catalyzed double [2+2+2] cycloaddition of 1,4-bis(diphenylphosphinoyl)buta-1,3-diyne with tethered diynes provides a straightforward, single-pot procedure for the synthesis of a new class of tropos blaryl diphosphine, NU-BIPHEP. This methodology represents a significant improvement on existing multistep procedures. Enantiopure Lewis acid platinum complexes of these diphosphines are highly efficient catalysts for carbonyl-ene and Diels-Alder reactions, and ruthenium diphosphine-diamine complexes catalyze the asymmetric reduction of ketones to give ee's that rival those obtained with their BINAP counterpart.