α-MsO/TsO/Cl Ketones as Oxidized Alkyne Equivalents: Redox-Neutral Rhodium(III)-Catalyzed CH Activation for the Synthesis of N-Heterocycles
作者:Da-Gang Yu、Francisco de Azambuja、Frank Glorius
DOI:10.1002/anie.201310272
日期:2014.3.3
α‐Halo and pseudohalo ketones are used for the first time as C(sp3)‐based electrophiles in transition‐metal‐catalyzed CHactivation and as oxidizedalkyneequivalents in RhIII‐catalyzed redox‐neutral annulations to generate diverse N‐heterocycles. This transformation is efficient and scalable. Due to the mild reaction conditions, a variety of functional groups could be tolerated.
Enantioselective Synthesis of Five-Membered-Ring Atropisomers with a Chiral Rh(III) Complex
作者:Saad Shaaban、Houhua Li、Felix Otte、Carsten Strohmann、Andrey P. Antonchick、Herbert Waldmann
DOI:10.1021/acs.orglett.0c03355
日期:2020.12.4
chemistry, and efficient methods for their synthesis are in high demand. This applies in particular to atropisomers derived from five-membered aromatic rings because their lower barrier for rotation among the biaryl axis limits their asymmetric synthesis. We report here an enantioselective C–H functionalization method using our chiral RhJasCp complex for the synthesis of the biaryl atropisomer types that
轴向手性阻转异构化合物广泛用于不对称催化和药物化学中,对合成的有效方法有很高的要求。这尤其适用于衍生自五元芳族环的阻转异构体,因为它们在联芳基轴之间旋转的较低阻挡层限制了它们的不对称合成。我们在这里报告了一种手性Rh Jas Cp络合物的对映选择性CH功能化方法,用于合成可从三个不同的五元环杂环中获得的联芳基阻转异构体类型。
Pd(II)-Catalyzed Asymmetric Oxidative Annulation of <i>N</i>-Alkoxyheteroaryl Amides and 1,3-Dienes
作者:Tao Zhang、Hong-Cheng Shen、Jia-Cheng Xu、Tao Fan、Zhi-Yong Han、Liu-Zhu Gong
DOI:10.1021/acs.orglett.9b00216
日期:2019.4.5
The first Pd(II)-catalyzedasymmetric oxidative annulation of N-alkoxyaryl amides and 1,3-dienes is reported, which features particular applicability for quick assembly of different types of chiral heterocycles with high yields and enantioselectivities. A novel chiral pyridine-oxazoline bearing a methoxyl group at the C-5 position and a gem-dimethyl group on the oxazoline moiety was found to be crucial
Rhodium-Catalyzed Annulative Coupling Using Vinylene Carbonate as an Oxidizing Acetylene Surrogate
作者:Koushik Ghosh、Yuji Nishii、Masahiro Miura
DOI:10.1021/acscatal.9b04254
日期:2019.12.6
Transition-metal-catalyzed C–Hactivation and subsequent oxidative cyclization with alkynes has been a powerful tool for the synthesis of polycyclic aromatic compounds. Despite the substantial progress in this field, it is still a significant challenge to establish synthetic methodologies for the construction of nonsubstituted vinylene-fused aromatics. We herein report a Rh(III)-catalyzed C–H/N–H annulation with vinylene
C–H/N–O activation with 1-bromoalkynes was accomplished within a chemoselective ruthenium(II) catalysis manifold by means of carboxylate assistance. The exceedingly mild reaction conditions set the stage for the positional selective annulations of bromoalkynes at an ambient reaction temperature of 25 °C, placing the organic substituent distal to nitrogen in isoquinolones with a regioselectivity that