Sequential insertion of formaldehyde and carbon monoxide into a sulfide-bridged Pd-Ge bond followed by reductive elimination to form a [1,3,2]oxathiagermolan-4-one

The reaction of (Et3P)(2)Pd(mu-S)Ge[N(SiMe3)(2)](2) (2) with paraformaldehyde under photolytic conditions results in the insertion of formaldehyde into the Pd-Ge bond, with bond cleavage, to give (Et3P)(2)Pd(mu-S)(muCH(2)O)Ge[N(SiMe3)(2)](2) (3). Subsequent addition of CO to 3 results in migratory insertion into the Pd-C bond, followed by rapid reductive elimination to regenerate the Pd-0 metal center and give a unique five-membered organic heterocycle, Ge[N(SiMe3)(2)](2)SC(O)CH2O (6). The X-ray crystal structure of the dppe (dppe = bis(diphenylphosphino)-ethane) derivative of 3, (dppe)Pd(mu-S)(muCH(2)O)Ge[N(SiMe3)(2)](2) (4), is reported.