Molybdenum stannyl

A Bm-containing molybdenum stannyl complex has been synthesized by oxidative addition of [Me2Sn(Bm)]Cl to Mo(0) precursors (Fig. 5.14) or through reactions of halostannanes with Na[Mo-(CO)3(Bm)]. The crystal structure of [Mo(CO)3(SnMe2Cl)(Bm)] in which Bm bridges both molybdenum and tin centers is also reported.26... 

Aminosugar-derived glycal 141 was obtained by this method from an appropriate chiral precursor 139 [237], Unexpectedly, however, reaction of tungsten intermediate 140 with tri- -butyltin triflate and triethylamine in ether gave the glycal 141 (in 85% yield) instead of the 1-stannyl derivative (O Scheme 47). The molybdenum carbonyl-triethylamine complex afforded the same product, although in a much lower yield. 

Hydrostannylation. Regioselective hydrostannylation of several types of alkynes (to yield mainly a-stannyl derivatives) is catalyzed by a molybdenum complex. 

Kazmaier and Jena have presented syntheses of stannylated, allyl (86) and vinylphosphonates (87) by molybdenum-catalyzed hydrostannation of the corresponding propargyl- (84) and alkynylphosphonate (85) derivatives (Scheme 27). " The stannylated phosphonates, obtained with high regios-electivities, were applied as building blocks in further modifications, such as Pd-catalyzed cross coupling reactions or iodination. 

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