The mechanism of the mild rhodium-catalyzed carbonylation and cyclization of N-alkylallylamines to γ-butyrolactams under COH2

✍ Scribed by Roberto A. Sánchez-Delgado; Ricardo Gomes da Rosa; Edgar Ocando-Mavarez

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 437 KB
• Volume: 108
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/1381-1169(95)00282-0

✦ Synopsis

The carbonylation and cyclization of N-alkylallylamines to y-butyrolactams is efficiently achieved by use of RhCI, 3H20/PPh, or RhCl(COXPPh,), as catalyst precursors under mild conditions (7O"C, 10 bar) when CO/H, (4: 1) mixtures are used instead of pure CO. Mechanistic studies on the Rh and the analogous Ir system allowed the deduction of a major catalytic cycle in which the active species is RhCI(CO),(PPh,), and the role of H, is the decomposition of an intermediate containing a coordinated carbamoyl fragment derived from a nucleophilic attack of the amine to a coordinated CO.