Development of New and Efficient Organic Transformations Catalyzed by Molybdenum

我们开发了一种以钼为原料的新型催化剂，该催化剂是由六甲基钼与丙烯基溴反应而成的。该催化剂促进了具有两个末端炔的二炔类化合物与炔丙基溴的[2+2+2]-共环化反应，生成了取代的溴化苄衍生物。当二炔类化合物既有端炔又有内炔时，与炔丙基溴化物反应生成环化的溴二烯衍生物，而没有加入炔丙基溴的炔烃部分。此外，乙酸烯丙基甲酯与丙烯基溴在正丙基甲苯的催化下反应生成了2-溴-1，3-丁二烯衍生物。并对这些反应的范围和局限性进行了研究。由于没有其他过渡金属络合物参与这些反应，我们的发现应该是钼的固有有机转化。

We developed a new catalyst based on molybdenum, which was made in situ by reaction of molybdenum hexacarbonyl with Propargyl bromide. The catalyst promoted [2+2+2]-cocyclization of diynes having both terminal alkynes with propargyl bromide to produce substituted benzyl bromide derivatives. When diynes had both terminal and internal alkynes, the reaction with propargyl bromide produced cyclized bromodiene derivative without incorporation of alkyne part of propargyl bromide. In addition, reaction of allenylmethyl acetate with propargyl bromide catalyzed by n-propargylmolubdenum gave 2-bromo-1,3-butadiene derivatives. The scope and limitation of these reactions was also investigated. Since no other transition metal complexes mediated these reactions, our findings should be inherent organic transformations of molybdenum.