New optically active organotin compounds for heterogeneous bimetallic catalysis

Chiral tin(IV) derivatives with two or three chiral centers adjacent to the metal (−)-Ment₂SnMe₂, (−)-Ment₂SnPh₂, (−)-Ment₃ SnCl, (−)-Ment₃SnH; (−)-Ment = (1R, 2S, 5R)-1-chloro-5-methyl-2-isopropylcyclohexane, R₂SnCH(Me)(n-Hex)]₂ (R = Bu or Ph) have been prepared either by the coupling of methylmagnesium chloride with tin halides or by the reaction of lithium stannates with optically active (2-octyl)tosylate. The stereospecificity of both processes was remarkably high, leading to new optically pure organotin reagents which have been fully characterized.