Fernández Maitane, Castaing Matthias, Willis Michael C
Department of Chemistry , University of Oxford , Chemical Research Laboratory , Mansfield Road , Oxford , OX1 3TA , UK . Email:
Chem Sci. 2017 Jan 1;8(1):536-540. doi: 10.1039/c6sc03066a. Epub 2016 Sep 9.
We demonstrate that a single Rh(i) complex can promote two mechanistically distinct C-C bond-forming reactions - alkyne hydroacylation and aryl boronic acid conjugate addition - to deliver substituted ketone products from the controlled assembly of three readily available fragments. This is a rare example of a Rh(i)/Rh(iii) cycle and a redox neutral Rh(i) cycle being promoted by a single catalyst. The process is broad in scope, allowing significant variation of all three reaction components. Incorporation of an enantiomerically pure bis-phosphine ligand renders the process enantioselective. Superior levels of enantioselectivity (up to >99% ee) can be achieved from using a two catalyst system, whereby two Rh(i) complexes, one incorporating an achiral bis-phosphine ligand and the second a chiral diene ligand, are introduced at the start of the reaction sequence.
我们证明，单一的铑（I）配合物可以促进两种机制不同的碳-碳键形成反应——炔烃氢酰化反应和芳基硼酸共轭加成反应，通过三个易于获得的片段的可控组装来生成取代酮产物。这是由单一催化剂促进铑（I）/铑（III）循环和氧化还原中性铑（I）循环的罕见例子。该过程适用范围广泛，所有三个反应组分都可以有很大变化。引入对映体纯的双膦配体可使该过程具有对映选择性。使用双催化剂体系可以实现更高水平的对映选择性（高达>99% ee），即在反应序列开始时引入两种铑（I）配合物，一种含有非手性双膦配体，另一种含有手性二烯配体。
