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 (2) with paraformaldehyde under photolytic
conditions results in the insertion of formaldehyde into the Pd−Ge bond, with bond cleavage,
to give (Et3P)2Pd(μ-S)(μCH2O)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 Pd0 metal center and give a unique five-membered organic heterocycle, (6). The X-ray crystal structure of the dppe (dppe = bis(diphenylphosphino)ethane) derivative of 3, (dppe)Pd(μ-S)(μCH2O)Ge[N(SiMe3)2]2 (4), is reported.