A Heteroleptic Dirhodium Catalyst for Asymmetric Cyclopropanation with α‐Stannyl α‐Diazoacetate. “Stereoretentive” Stille Coupling with Formation of Chiral Quarternary Carbon Centers
作者:Fabio P. Caló、Alois Fürstner
DOI:10.1002/anie.202004377
日期:2020.8.10
The heteroleptic dirhodium paddlewheel catalyst 7 with a chiral carboxylate/acetamidate ligand sphere is uniquely effective in asymmetric [2+1] cycloadditions with α‐diazo‐α‐trimethylstannyl (silyl, germyl) acetate. Originally discovered as a trace impurity in a sample of the homoleptic parent complex [Rh2((R )‐TPCP)4] (5 ), it is shown that the protic acetamidate ligand is quintessential for rendering
具有手性羧酸盐/乙酰氨基甲酸酯配体球的杂多丙二酸桨轮催化剂7在乙酸α-重氮-α-三甲基锡烷基(甲硅烷基,胚芽基)的不对称[2 + 1]环加成中具有独特的作用。最初在同质母体复合物[Rh 2((R)-TPCP)4 ](5)的样品中作为痕量杂质发现,表明质子对乙酰氨基酸盐配体对于精制7具有典型意义高对映选择性。‐NH基团被认为通过配体氢键将随后的金属卡宾锁定在适当的位置。生成的甲锡烷基化环丙烷经历“立体固位”交叉偶联,这首次表明,斯蒂勒-米吉塔反应甚至可以形成手性季碳中心。