Synthesis of a Novel Ate Tin Hydride Complex Bearing a Nucleophilic Iodide Substituent and 1,4-Regioselective Reduction of α,β-Unsaturated Aldehydes

A novel ate tin hydride complex, Li + [ n -Bu 2 SnI 2 H] - ( I), was synthesized and characterized on the basis of its 119 Sn NMR spectrum as a trigonal bipyramid (TBP) structure, in which two iodine atoms and one hydrogen atom occupy the apical and the equatorial positions, respectively. The apical iodine has much greater nucleophilicity than the hydrogen, so that the attack by iodide precedes the reduction by hydrogen, achieving regioselective 1,4-reduction of α,β-unsaturated aldehydes.