Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, D-48149 Münster, Germany.
Chem Commun (Camb). 2011 Jul 28;47(28):7917-32. doi: 10.1039/c1cc10528k. Epub 2011 Apr 28.
The direct enantioselective 1,4-addition of water to α,β-unsaturated acceptors is an open challenge in asymmetric catalysis. Enantioselective conjugate addition of either silicon or boron nucleophiles and subsequent enantiospecific oxidative degradation of the carbon-element bond represents, however, an attractive detour. A single extra step thereby enables an indirect enantiocontrolled construction of (in a broader sense) aldols from α,β-unsaturated carbonyl and carboxyl compounds. While that strategy had been obvious for a long time, it was recent stunning progress in transition metal-catalysed activation of interelement linkages that brought about the solution to that long-standing problem. A concise introduction of existing protocols for stereoselective 1,4-addition of oxygen nucleophiles is followed by a comprehensive summary of the recent rapid advances in transition metal-catalysed (and metal-free) asymmetric conjugate transfer of nucleophilic silicon and boron onto α,β-unsaturated acceptors.
α,β-不饱和受体的水的直接对映选择性 1,4-加成是不对称催化中的一个开放性挑战。然而，硅或硼亲核试剂的对映选择性共轭加成以及随后的碳-元素键的对映选择性氧化降解代表了一种有吸引力的迂回途径。因此，单个额外步骤可以从α,β-不饱和羰基和羧基化合物间接对映控制地构建（广义上的）羟醛。虽然该策略已经很明显了很长时间，但正是过渡金属催化的元素间键合活化方面的最新惊人进展解决了这个长期存在的问题。本文在简要介绍氧亲核试剂的立体选择性 1,4-加成现有方法之后，全面总结了过渡金属催化（和无金属）不对称共轭转移亲核硅和硼到α,β-不饱和受体的最新快速进展。
