Pseudohalides alkyne reactions

Representatives of the little-known class of silicon-copper compounds are formed in situ from organosilyllithium compounds and Cud) halides or pseudohalides they can then undergo cleavage at the Si-Cu bond with alkynes (entries 123 and 124). The reaction, particularly with (R3Si)2CuLi, is regiospecific, and a route to useful vinyl derivatives. 

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