Ligand dependence of molybdenum-catalyzed alkylations. Molybdenum-isonitrile complexes as a new class of highly reactive alkylation catalysts
作者:Barry M. Trost、Craig A. Merlic
DOI:10.1021/ja00182a018
日期:1990.12
generates the most effective molybdenum catalysts known to date. The reactive catalyst proved to be Mo(RNC) 4 (CO) 2 . With this new catalyst, a much broader range of substrates can be employed including many that failed or reacted very poorly by using molybdenum hexacarbonyl. The regioselectivity also differs from that obtained with molybdenum hexacarbonyl. The stereochemistry of the reaction proceeds with
已经制备了一系列带有-α-二亚胺、N,N'-二亚芳基乙二胺和异腈配体的钼配合物,并评估了它们通过使用乙酸烯丙酯,尤其是烯丙基砜催化烷基化的能力。与bpyMo(CO) 4 相比,(bpy)Mo(CH 3 CN)(CO) 3 被证明是一种非常有效的催化剂。将异腈配体添加到六羰基钼上可产生迄今为止已知的最有效的钼催化剂。反应性催化剂被证明是Mo(RNC) 4 (CO) 2 。使用这种新催化剂,可以使用更广泛的底物,包括许多因使用六羰基钼而失效或反应非常差的底物。区域选择性也不同于使用六羰基钼获得的区域选择性。即使在产生与六羰基钼的非对映异构体混合物的条件下,反应的立体化学也以非常干净的净保留构型进行。提出了一种解释看似不同的催化剂复合物的机械原理