Hydrostannylation of Ketones and Alkynes with LSnH [L = HC(CMeNAr)(2), Ar=2,6-iPr(2)C(6)H(3)]

Abstract

The reactions of the stable beta-diketiminate tin(II) hydride LSnH [L = HC(CMeNAr)(2), Ar = 2,6-iPr(2)C(6)H(3)] with different ketones (Ph2CO, 2-Py2CO, cyPr(2)CO, and 2-C4H3SCOCF3) generated a variety of tin(II) alkoxides (1-4) in high yield. The activated terminal alkynes (HC CCO2R, R = Me, Et) react with LSnH to yield the tin(II) substituted terminal alkenes (5-6) instead of dihydrogen elimination although the Sn-H and C-H bonds are differently polarized. Furthermore, LSnH reacts with disubstituted alkyne (RO2CC=CCO2R, R = Et, tBu) in toluene at room temperature to form the stannylene substituted internal alkenes (7-8). Compounds 1-8 were characterized by microanalysis and multinuclear NMR spectroscopy. Moreover compounds 3, 4, 5, and 7 were characterized by X-ray crystallography, and the resulting structures confirmed the monomeric nature, in which the tin centers reside in a trigonal-pyramidal environment.