Site-selective enzymatic C‒H amidation for synthesis of diverse lactams
作者:Inha Cho、Zhi-Jun Jia、Frances H. Arnold
DOI:10.1126/science.aaw9068
日期:2019.5.10
rings of varying size (see the Perspective by Hepworth and Flitsch). The enzyme directs amidation to the desired position and simultaneously prevents other side reactions. Science, this issue p. 575; see also p. 529 Evolved enzymes selectively form β-, γ-, and δ-lactams from simple precursors. A major challenge in carbon‒hydrogen (C‒H) bond functionalization is to have the catalyst control precisely where
Regiodivergent Iridium(III)-Catalyzed Diamination of Alkenyl Amides with Secondary Amines: Complementary Access to γ- or δ-Lactams
作者:John H. Conway、Tomislav Rovis
DOI:10.1021/jacs.7b11455
日期:2018.1.10
Alkenyl N-pivaloylhydroxamates undergo an Ir(III)-catalyzed diamination of the alkene with simple exogenous secondary amines under extraordinarily mild reaction conditions. The regioselectivity of the diamination is controlled by the solvent and the electronics of the cyclopentadienyl (Cpx) ligand on Ir. On the basis of a set of mechanistic experiments, we propose that the relative rates of Ir(V)-nitrenoid
烯基 N-新戊酰基异羟肟酸酯在非常温和的反应条件下,通过 Ir(III) 催化的烯烃与简单的外源仲胺进行二胺化。二化反应的区域选择性受溶剂和 Ir 上环戊二烯基 (Cpx) 配体的电子控制。在一组机械实验的基础上,我们提出 Ir(V)-nitrenoid 形成的相对速率与外源胺对酰胺-Ir-配位烯烃的攻击决定了反应的结果。
Ligand Controlled Ir-Catalyzed Regiodivergent Oxyamination of Unactivated Alkenes
作者:Honghui Lei、John H. Conway、Caleb C. Cook、Tomislav Rovis
DOI:10.1021/jacs.9b06366
日期:2019.7.31
An intramolecular Ir(III)-catalyzed regiodivergent oxyamination of unactivated alkenes provides valuable γ-lactams, γ-lactones and δ-lactams. The regioselectivity is controlled by the electronically tunable cyclopentadienyl Ir(III)-complexes enabling oxyamination via either 5-exo or 6-endo pathways. With respect to the mechanism, we propose a highly reactive [3.1.0] bicycle intermediate derived from