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

Yang, L.; Zheng, H.; Luo, L.; Nan, J.; Liu, J.; Wang, Y.; Luan, X.

Journal of the American Chemical Society 137(15): 4876-4879

ISSN/ISBN: 1520-5126

2015

PMID: 25851252

DOI: 10.1021/jacs.5b01285

Document: 007645621

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).