“…In this work, different carbonyl complexes and solvents were examined in detail, and it was found that the [Rh(CO) 2 Scheme 24 Rhodium-catalyzed carbonylation of alkene-alkyne using aldehyde as CO source [55], based on previous work on the rhodium-catalyzed carbonylation of isoxazolidines with regioselective insertion of CO into the N-O bond affording tetrahydro-1,3-oxazin-2-ones [56]. When N-benzylisothiazolidine is reacted with 5 mol% of (1,5-cyclooctadiene)rhodium(I) dimer in benzene in the presence of 1,000 psi of carbon monoxide at 130 C for 24 h, a 58% yield of 2H-1,3-thiazin-2-one can be achieved, and the addition of 5 mol% of potassium iodide can increase the yield to 70% (Scheme 28).…”