Titanium-Catalyzed Hydroalumination of Conjugated Dienes: Access to Fulvene-Derived Allylaluminium Reagents and Their Diastereoselective Reactions with Carbonyl Compounds
作者:Jomy Joseph、Florian Jaroschik、Dominique Harakat、K. V. Radhakrishnan、Jean-Luc Vasse、Jan Szymoniak
DOI:10.1002/chem.201304775
日期:2014.4.25
The described titanium‐catalyzed hydroalumination of conjugated dienes opens up a new way to allylaluminium reagents. The reaction is carried out by using diisobutylaluminium hydride (DIBAL‐H) and a catalytic amount of [Cp2TiCl2] (Cp=cyclopentadienyl). When applied to mono‐ and disubstitued pentafulvenes, this reaction proceeds in a highly endocyclic manner. The formed allylaluminium compounds react
钛催化的共轭二烯加氢铝化为烯丙基铝试剂开辟了一条新途径。通过使用氢化二异丁基铝(DIBAL-H)和催化量的[Cp 2 TiCl 2](Cp =环戊二烯基)。当将其用于单和五元五联戊酸酯时,该反应会以高度内环的方式进行。形成的烯丙基铝化合物与醛和酮发生区域和立体选择性反应,生成均聚烯丙醇,适合作为功能化环戊酮的合成子。还研究了这种方法对简单二烯的扩展。在提出的机理中,最初形成的双金属物种(Ti / Al)参与了两个可能的催化循环,这些循环包括直接加氢铝化或/和加氢钛化,然后进行钛到铝的金属转移。