Coordination of (β-N-sulfonylaminoalkyl)phosphines and their analogous arsines to PdII and PtII. Application of the Pd-complexes as chiral catalysts in asymmetric hydrosilylation of 1,3-dienes†
an efficient asymmetric denitrogenative cycloaddition of benzotriazoles with cyclic and acyclic 1,3-dienes enabled by Pd and chiral sulfonamide phosphine ligand. A variety of substituted hexahydrocarbazoles and indolines were delivered in good yields with high ee values. Interestingly, a pair of enantiomers could be obtained with the use of Xu1 and PC2 with the same absolute configuration. The synthetic
不对称脱氮环加成已成为构建手性氮杂杂环的有力工具。然而,迄今为止,仅探索了苯并三唑与不饱和烃的不对称脱氮环加成的一个例子,因为苯并三唑开环生成α-亚氨基金属类卡宾是一种热力学不利的过程。我们在此报告了由 Pd 和手性磺酰胺膦配体实现的苯并三唑与环状和非环状 1,3-二烯的有效不对称脱氮环加成反应。各种取代的六氢咔唑和二氢吲哚均以良好的收率和高 ee 值交付。有趣的是,使用Xu1和PC2可以获得一对对映异构体具有相同的绝对配置。还展示了光学活性六氢咔唑的合成效用。
(NHC)NiH-Catalyzed Intermolecular Regio- and Diastereoselective Cross-Hydroalkenylation of Endocyclic Dienes with α-Olefins
作者:Xiaoyan Lian、Weihao Chen、Liang Dang、Yuchen Li、Chun-Yu Ho
DOI:10.1002/anie.201703706
日期:2017.7.24
3‐product selectivity (i.e., with the H atom at C4 and the alkenyl group at C3 of the diene) was observed, which is different from the selectivity of known dimerizations of α‐olefins with both acyclic Co and Fe systems. The influence of the various substituents on the NHC, 1,3‐diene, and α‐olefin on the chemo‐, regio‐, and diastereoselectivity was studied. High levels of chirality transfer were observed
使用一组中性(NHC)Ni II H(OTf)催化剂和阳离子Ni II,可以在最少被α-烯烃取代的位置上实现内环1,3-二烯的高选择性交叉氢化烯基化具有新型NHC配体的催化剂。在杂原子辅助下,通常以等量的两种底物和2-5 mol%的催化剂负载量获得高收率的跳过的二烯。观察到稀有的4,3-产物选择性(即,H原子位于二烯的C4和烯基在C3上),这与已知的α-烯烃在无环Co和Fe系统中的二聚反应的选择性不同。研究了各种取代基对NHC,1,3-二烯和α-烯烃的化学,区域和非对映选择性的影响。用手性环己二烯衍生物观察到高水平的手性转移。
(Pd-OTMM or Pd-NTMM) with cyclic or acyclic 1,3-dienes via a pathway terminated with C–N or C–O bond formation, delivering the highly substituted or fused pyrrolidine and tetrahydrofuran rings in high yields with excellent regio-, diastereo-, and enantioselectivity. Engineering the PC-Phos, one of the chiral sulfinamide phosphine (Sadphos) type ligands, by introducing the di-tert-butyl or/and 3,5-difluorophenyl
Photoinduced Cobalt Catalysis for the Reductive Coupling of Pyridines and Dienes Enabled by Paired Single‐Electron Transfer**
作者:Jingyang Qin、Manuel Barday、Samikshan Jana、Nil Sanosa、Ignacio Funes‐Ardoiz、Christopher J. Teskey
DOI:10.1002/anie.202310639
日期:2023.11.6
A mild, regioselective method for the hydropyridylation of diene feedstocks is reported, and is amenable to late-stage-functionalisation. Experiments and DFT calculations suggest a mechanism involving non-reversible hydrogen atom transfer, resulting in a reaction that is uniquely selective for dienes in the presence of other olefins.
Dual‐Catalysed Intermolecular Reductive Coupling of Dienes and Ketones**
作者:Victor J. Mayerhofer、Martina Lippolis、Christopher J. Teskey
DOI:10.1002/anie.202314870
日期:2024.1.8
A mild, catalytic method for the intermolecular reductive coupling of feedstock dienes and styrenes with ketones and imines is reported. Applications of this straightforward approach include the efficient synthesis of drug molecules and site-selective late-stage functionalisation.