α-Silylamines, also called silylmethylamines (SMAs), and their derivatives have attracted considerable attention due to their biological activities and their applications in synthetic transformations ever since they were first described in 1951. Although numerous SMAs have been characterized and used in various applications, few reports exist of α-tertiary amines containing α-silyl groups (R2SMA), in part because they cannot be prepared efficiently by current methods.
The research group headed by Prof. LU ChongDao at Xinjiang Technical Institute of Physics and Chemistry (XTIPC), Chinese Academy of Sciences (CAS) has developed an efficient and flexible route for the synthesis of α-tertiary (α,α-dibranched) α-silylamines via sequential reactions of sulfonylimidates using readily available silyllithium reagents and Grignard reagents. The procedure allows successive formation of C–Si/C–C bonds in a single flask. Meanwhile, three kinds of products (silyl N,O-aminal, acylsilane and acylsilane-derived imine) can be obtained when the first step of the reaction (silyllithium addition) quenched by different conditions.
The three-component coupling of aryl tosylimidates, silyllithium, and Grignard reagents in a single flask enables the rapid construction of diverse bulky α-silylamine derivatives. It can be used in some natural products which contain the skeletal structure of α- silylamine and α- silyl amino acid.
The results have been published in Organic Letters, 2012, 14 (11) : 2906–2909.
This work was supported by the National Natural Science Foundation of China, the “Western Light” program, and the Chinese Academy of Sciences.
