Synthesis of Isothiazoles and Isoselenazoles through Rhodium-Catalyzed Oxidative Annulation with Elemental Sulfur and Selenium
摘要:
A rhodium-catalyzed oxidative annulation of benzimidates with elemental sulfur for the direct construction of isothiazole rings is reported. The proposed reaction mechanism involving Rh(I)/Rh(III) redox is supported by a stoichiometric reaction of metallacycle species as well as DFT calculations. This method is also applicable to selenium cyclization to produce isoselenazole derivatives. The alkoxy substituent at C3 can be used for further functionalization of the azole core.
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
Direct Synthesis of Biphenyl-2-carbonitriles by Rh(III)-Catalyzed C–H Hiyama Cross-Coupling in Water
作者:Xiuqi Zhang、Fukuan Zhang、Xiaolan Li、Ming-Zhu Lu、Xin Meng、Lei Huang、Haiqing Luo
DOI:10.1021/acs.orglett.2c01754
日期:2022.7.22
This method represents an efficient rhodium(III)-catalyzed o-C–H arylation of readily available benzimidate derivatives with diverse arylsilanes in water as a sustainable solvent, enabling the straightforward synthesis of potentially useful biphenyl-2-carbonitrile derivatives. This silicon-based protocol employs benzimidates as both an efficacious directing group and the source of a nitrile group.
A Ru(II)-catalyzed C–H alkenylation of benzimidates with unactivated alkenes providing ortho-alkenylated benzonitriles in good to excellent yields in a highly regio- and stereoselective manner is described. In the reaction, an imidate group converted into a nitrile under the reaction conditions. The alkenylation reaction was compatible with various substituted benzimidates as well as functionalized
A Ru(II)-catalyzed efficient synthesis of 1H-isoindoles via the cyclization of benzimidates with alkenes has been demonstrated. This methodology exhibits high compatibility with various functionalized activated and unactivated olefins containing different sensitive functional groups. This protocol provides an effective method for synthesizing various 1H-isoindole derivatives in decent to excellent
Ru(II) 催化通过苯甲亚胺酯与烯烃的环化有效合成 1 H -异吲哚已被证明。该方法与含有不同敏感官能团的各种官能化活化和未活化烯烃表现出高度相容性。该方案提供了一种以良好的收率合成各种 1 H -异吲哚衍生物的有效方法。值得注意的是,实现了苯甲亚胺酯与未活化烯烃的邻位烯基化。已提出一种潜在的反应机制,涉及 C-H 激活、1,2 插入和氮杂迈克尔加成后的β-氢化物消除。
Rh(III)-Catalyzed Dual C–H Activation/Cascade Annulation of Benzimidates and CF<sub>3</sub>-Imidoyl Sulfoxonium Ylides for the Synthesis of Trifluoromethyl-Decorated Benzo[<i>de</i>][1,8]naphthyridines