(4 + 2) Annulation of Cl - NH 3 + CH 2 SiMe 2 CH 2 Cl and Propynones for the Synthesis of 1,3-Azasilinones.

A useful 1,3- N , Si reagent (Cl - NH 3 + CH 2 SiMe 2 CH 2 Cl) and its (4 + 2) annulation with propynones have been developed. The (4 + 2) annulation is promoted by NaHCO 3 via an intermolecular N -1,4-addition/intramolecular alkylation process, leading to 1,3-azasilinones in good yields. Diverse functionalization of the alkene, carbonyl, and nitrogen moieties on the 1,3-azasilinone has been demonstrated, showcasing the potential of the approach in the synthesis of bioactive molecules containing silaazacycles.