Preparation of Chiral Allenes through Pd-Catalyzed Intermolecular Hydroamination of Conjugated Enynes: Enantioselective Synthesis Enabled by Catalyst Design
作者:Nathan J. Adamson、Haleh Jeddi、Steven J. Malcolmson
DOI:10.1021/jacs.9b02637
日期:2019.5.29
surrogate to afford primary amines in a two-step/one-pot process. Examination of chiral catalysts revealed a high degree of reversibility in the C-N bond formation that negatively impacted enantioselectivity. Consequently, an electron-poor ferrocenyl-PHOX ligand was developed to enable efficient and enantioselective enyne hydroamination.
Cascade reactions are an important strategy in reaction design, allowing streamlining of chemical synthesis. Here we report a cascade Suzuki–Miyaura/Diels–Alder reaction, employing vinyl Bpin as a bifunctional reagent in two distinct roles: as an organoboron nucleophile for cross-coupling and as a Diels–Alder dienophile. Merging these two reactionsenables a rapid and operationally simple synthesis
Enantioselective hydroacylation of N-vinylindole-2-carboxaldehydes
作者:Avipsa Ghosh、Levi M. Stanley
DOI:10.1039/c4cc00210e
日期:——
We report rhodium-catalyzed hydroacylations of N-vinylindole-2-carboxaldehydes that form chiral, non-racemic 2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-ones in high yields with excellent enantioselectivities.
Iridium-Catalyzed Enantioselective Hydrogenation of Alkenylboronic Esters
作者:Adnan Ganić、Andreas Pfaltz
DOI:10.1002/chem.201200246
日期:2012.5.29
iridium complex derived from a phosphino–imidazoline ligand is a highly efficient catalyst for the asymmetric hydrogenation of terminal vinyl boronic esters (see scheme). On the other hand, trisubstituted alkenyl‐boronates can be reduced with high activity and good to excellent enantioselectivity employing a pyridine–phosphinite ligand.
halogenation/semipinacol rearrangement was realized through a ligand-controlled stereodivergent kinetic resolution. An array of optically active quinolone derivates and quinoline alkaloids were provided simultaneously by using a chiral Sc(OTf)3/N,N′-dioxide complex as catalyst. The reaction mechanism was proposed to rationalize the reaction process and enantiocontrol.
通过配体控制的立体发散动力学分辨率实现了高度对映选择性的卤化/半匹萘醇重排。通过使用手性 Sc(OTf) 3 / N , N '-二氧化物配合物作为催化剂,同时提供了一系列光学活性喹诺酮衍生物和喹啉生物碱。提出了反应机理以合理化反应过程和对映控制。