Asymmetric Copper(I)-Catalyzed Azide–Alkyne Cycloaddition to Quaternary Oxindoles

Feng Zhou, Chen Tan, Jing Tang, Yan-Yan Zhang, Wei-Ming Gao, Hai-Hong Wu, Yi-Hua Yu, and Jian Zhou 

 J. Am. Chem. Soc., 2013, 135 (30), pp 10994–10997 

DOI: 10.1021/ja4066656