Pd/PC‐Phos‐Catalyzed Enantioselective Intermolecular Denitrogenative Cyclization of Benzotriazoles with Allenes and N‐Allenamides

Abstract

Reported herein is an asymmetric Pd/PC-Phoscatalyzedd enitrogenative cyclization of benzotriazoles with allenes and N-allenamides,r epresenting the first example of enantioselective denitrogenative cyclizations of benzotriazoles. Aseries of optically active 3-methyleneindolines were obtained in good yields with high ee values.The use of inexpensive and readily available starting materials,h igh regio-and enantioselectivity,abroad substrate scope,m ild reaction conditions,n o need for base,a sw ell as versatile functionalization of the 3methyleneindolines make this approach attractive.

Ming‐Phos/Gold(I)‐Catalyzed Stereodivergent Synthesis of Highly Substituted Furo[3,4‐d][1,2]oxazines†

“…Therefore, the simple and easily prepared chiral ligands with multi sites for modification are highly desirable. Recently, our group developed a new type of SadPhos (Ming‐Phos, Xiang‐Phos, PC‐Phos, Xu‐Phos, WJ‐Phos and Xiao‐Phos), which have diverse sites for modification and could be easily prepared in good yields from inexpensive commercially available chiral tert ‐butylsulfinamide and could be applied to address many challenging reactions. For example, we reported a gold‐catalyzed diastereo‐ and enantioselective [3+3] cycloaddition of 2‐(1‐alkynyl)‐2‐alken‐1‐ones with nitrones to afford an efficient synthetic route to construct chiral highly substituted furo[3,4‐ d ][1,2]oxazines (Scheme ) [5a] .…”