Palladium-Catalyzed Dynamic Kinetic Asymmetric Transformation of Racemic Biaryls: Axial-to-Central Chirality Transfer

J Am Chem Soc. 2015 Apr 22;137(15):4876-9. doi: 10.1021/jacs.5b01285. Epub 2015 Apr 10.

Abstract

The first dynamic kinetic asymmetric transformation of racemic biaryl substrates on the basis of axial-to-central chirality transfer has been realized. Chiral Pd-NHC complexes were found to catalyze the dynamic kinetic asymmetric spiroannulation of 4-(2-bromoaryl)-naphthalen-1-ols (or 2'-bromo-[1,1'-biphenyl]-4-ols) with internal alkynes, affording a series of enantioenriched spirocyclic products bearing an all-carbon quaternary stereocenter in good yields (up to 95%) with excellent enantioselectivities (up to 97% ee).