Synthesis of Aryl Trimethylstannanes from Aryl Amines: A Sandmeyer-Type Stannylation Reaction

摘要

The cross-coupling reaction with organotin reagents, namely the Stille coupling reaction, has been well-established as a powerful C—C bond forming method in organic synthesis. Moreover, the Ar—Sn bond can also be employed in various functional-group transformations, such as C—N, C—F, and C—OCF3 bond formation. The wide application of Stille coupling has created considerable need for the easy access to aryl stannane compounds. However, the methods for the synthesis of functionalized aryl stannane compounds are still very limited. The traditional method for preparing aryl stannane compounds is by the reaction of aryl magnesium, -lithium, or -zinc reagents with trialkyl tin chloride (Scheme 1a). A different strategy is the nucleophilic substitution between aryl halides or aryl ammonium salts and trialkyl stannyl anion (Scheme 1 b). Moreover, palladium-catalyzed direct stannylation from aryl halides/ArOTf has also been reported, which uses hexaalkyl distannane as the tin source (Scheme 1c).