Enantioselective Hydrogenation and Transfer Hydrogenation of Bulky Ketones Catalysed by a Ruthenium Complex of a Chiral Tridentate Ligand
作者:M. Belén Díaz-Valenzuela、Scott D. Phillips、Marcia B. France、Mary E. Gunn、Matthew L. Clarke
DOI:10.1002/chem.200801929
日期:2009.1.19
substrates such as bulky heterocyclic ketones. Unusually for a pressure hydrogenation catalyst, similar enantioselectivity can be obtained under transfer hydrogenation conditions. The transfer hydrogenations are somewhat slower than the pressure hydrogenations, but this drawback is readily overcome, since we have discovered that a microwave accelerated transfer hydrogenation of the above ketones occurs within
报道了对一类新型三齿-Ru配合物催化的叔烷基酮的对映选择性加氢的研究。与广泛研究的[RuCl 2(diphos)(二伯胺)]配合物相比,这种新型的氢化催化剂可将这些反应性较低的笨重酮平稳还原,其ee最高可达94% 。相同的催化剂体系还可以选择性地还原其他潜在有问题的底物,例如庞大的杂环酮。通常对于加压氢化催化剂,在转移氢化条件下可以获得相似的对映选择性。转移氢化比压力氢化稍慢,但是这个缺点很容易克服,因为我们发现上述酮的微波加速转移氢化在约90°C的20分钟内发生,其选择性与在压力下获得的选择性相似。氢化系统。