Hydrostannylation of Olefins by a Hydridostannylene Tungsten Complex

Reaction of the aryltin(II) hydride {AriPr6Sn(μ-H)}2 (AriPr6 = −C6H3-2,6-(C6H2-2,4,6-iPr3)2) with two equivalents tungsten carbonyl THF complex, [W(CO)5(THF)], afforded divalent tin transition metal W(CO)5{Sn(AriPr6)H}, (1). Complex 1 reacted rapidly ethylene, or propylene under ambient conditions to yield corresponding hydrostannylated organometallic species, W(CO)5{Sn(AriPr6)(Et)} (2), W(CO)5{Sn(AriPr6)(nPr)} (3), via olefin insertion into Sn–H bond. Treatment Lewis base dbu (dbu 1,8-diazabicycloundec-7-ene) acid–base W(CO)5{Sn(AriPr6)(dbu)H} (4), indicating that acidity atom is preserved in 4. The complexes were characterized by X-ray crystallography, and UV–visible, FT-IR, multinuclear NMR spectroscopies. DFT calculations suggest hydrostannylation ethylene proceeds coordination atom, then Further computational study on reactivity toward Ph3SiH indicated rate-determining step involves metathesis reaction a Sn–C/Si–H bond very high energy barrier 71.3 kcal/mol. calculated proton abstraction product dbu, [W(CO)5{Sn(AriPr6)}]+[H(dbu)]−, 18.2 kcal/mol less stable than observed