Collect. Czech. Chem. Commun. 2002, 67, 587-595

Reinvestigation of Reaction of (2-Ethoxyvinyl)stannanes with Acetyl Bromide

Tomáš Lébla,*, Jaroslav Holečeka, Marek Dymáka and Dirk Steinbornb

a Department of General and Inorganic Chemistry, University of Pardubice, Čs. Legií 565, 532 10 Pardubice, Czech Republic
b Department of Inorganic Chemistry, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Straße 2, 06120 Halle (Saale), Germany


Four analogous (2-ethoxyvinyl)stannanes (E/Z)-Bu3SnC(R)=CHOEt (R = Bu, H) were prepared and characterised using 1H, 13C, 119Sn, 1H-13C HMQC, 1H-13C HMBC, and 1H-119Sn HMQC NMR spectroscopy. The course of their reactions with acetyl bromide was studied by NMR spectroscopy. Although tributyltin bromide, ethyl acetate and the coresponding alkyne were identified as reaction products, this present reinvestigation showed unambiguously that heterolytic fragementation reactions, as stated previously, did not take place. Acetyl bromide cleaves the Sn-C= bond yielding tributyltin bromide and vinyl ethers. Subsequent decomposition of vinyl ethers and impurities in the starting stannane is the source of ethyl acetate and the alkyne, respectively.

Keywords: Tin; Stannanes; Reaction mechanisms; Kinetics; NMR spectroscopy; Tin-carbon bond cleavage; Heterolytic fragmentation.

References: 18 live references.