Stannylation of unsaturated carbon–carbon bonds by tin tetrachloride

The reactions of tin tetrachloride and four terminal alkynes (PhCCH, tBuCCH, nBuCCH, HOCH2CCH), norbornene, and norbornadiene in dichloromethane or chloroform solution lead to the formation of stannylation products, which were characterized by 1H, 13C and 119Sn NMR spectroscopy. Virtually complete α-regioselectivity was obtained in reaction of all four alkynes without any effect of the relative steric bulk of the substituent R at the triple bond of alkyne RCβCαH. The reaction of norbornene and norbornadiene with SnCl4 is stereoselective, giving an exo stannylation product.

Graphical abstractThe reactions of tin tetrachloride and four terminal alkynes (PhCCH, tBuCCH, nBuCCH, HOCH2CCH), norbornene, and norbornadiene in dichloromethane or chloroform solution lead to the formation of stannylation products, which were characterized by 1H, 13C and 119Sn NMR spectroscopy. Virtually complete α-regioselectivity was obtained in reaction of all four alkynes. Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The reactions of SnCl4 and four terminal alkynes lead to the formation of stannylation products. ► Stannylation products were characterized by 1H, 13C and 119Sn NMR spectroscopy. ► Virtually complete α-regioselectivity was obtained in reaction of all four alkynes. ► The stannylation of norbornene is stereoselective, giving an exo product.