Iron Porphyrin Catalyzed Insertion Reaction of N-Tosylhydrazone-Derived Carbenes into X-H (X = Si, Sn, Ge) Bonds

An efficient Fe(TPP)Cl catalyzed insertion reaction of in situ generated benzylic carbenes from N-tosylhydrazones into X-H (X = Si, Sn, Ge) was developed. Silanes bearing tertiary, secondary, and primary (3 degrees, 2 degrees, and 1 degrees) Si-H bonds all reacted well to afford insertion products in moderate to high yields (up to 97%), and the reaction time could be significantly shortened to 1 h under microwave irradiation. A programmable stepwise double insertion strategy was developed for the synthesis of unsymmetrical tetrasubstituted silanes.