Organometallic reactions. Part XIV. The decarboxylation of trialkyltin carbamates by isocyanates and isothiocyanates: a new route to carbodi-imides
Abstract
Two aspects of organometallic addition reactions are discussed. In the first, one acceptor, A2B2, displaces another, A1
B1, from the adduct MABX. M–A1–B1–X + A2
B2→ M–A2–B2–X + A1
B1
In the second, exchange of the groups X and A between the addendum MXM and the acceptor AB, is brought about by an addition–elimination sequence. M–X–M + A
B → M–A–B–X–M → M–A–M + X
B
Tributyltin carbamates have been shown to react by the first process with isocyanates to give tributyltin derivatives of ureas. The same carbamates react with isothiocyanates by a combination of the two processes and the reaction provides a new route to carbodi-imides.