Capture of an In Situ Formed Distanna-S-heterocyclic Carbene

Area of Science:

• Organometallic Chemistry
• Main Group Chemistry
• Carbene Chemistry

Background:

• Distannenes, compounds featuring a tin-tin double bond, are reactive intermediates.
• Tin-carbon chemistry is crucial for developing new materials and catalysts.
• S-heterocyclic carbenes (SHCs) are versatile ligands and synthetic building blocks.

Purpose of the Study:

• To investigate the reactivity of a planar distannene, Sn2(TIPS)4, with carbon disulfide (CS2).
• To explore the formation and utility of novel S-heterocyclic carbene (SHC) derivatives.
• To synthesize and characterize new organotin compounds and palladium complexes.

Main Methods:

• Reaction of Sn2(TIPS)4 with CS2.
• Isolation and characterization of tetrathiaethylene derivatives and stannaethene SHC═Sn(TIPS)2.
• Complexation of SHCs with palladium.
• Capture of SHCs with B(C6F5)3.
• Theoretical calculations of frontier orbitals.

Main Results:

• The reaction of Sn2(TIPS)4 with CS2 leads to the dimerization of SHCs, forming tetrathiaethylene derivatives.
• The intermediary SHCs can be transferred to palladium as ligands or captured by B(C6F5)3.
• A new pathway for the formation of stannaethene SHC═Sn(TIPS)2 was established.
• Theoretical calculations revealed a high π-acceptor character for the SHC ligand.

Conclusions:

• The study demonstrates a novel synthetic route to SHCs from distannenes and CS2.
• The generated SHCs exhibit versatile reactivity as ligands and synthetic intermediates.
• The findings expand the scope of organotin chemistry and carbene transfer reactions.