1.
Angew Chem Int Ed Engl
; 53(24): 6220-3, 2014 Jun 10.
Artigo
em Inglês
| MEDLINE
| ID: mdl-24802937
RESUMO
Catalytic asymmetric synthesis of unsymmetrical triarylmethanes with a chiral all-carbon quaternary center was achieved by using a chiral bifunctional quaternary phosphonium bromide catalyst in the S(N)Ar reaction of 3-aryloxindoles under phase-transfer conditions. The presence of a urea moiety in the chiral phase-transfer catalyst was important for obtaining high enantioselectivity in this reaction.