Catalyst-Controlled [3 + 2] and [4 + 2] Annulations of Oximes with Propargyl Alcohols: Divergent Access to Indenamines and Isoquinolines
作者:Wanchun Gong、Zhi Zhou、Jingjing Shi、Bo Wu、Biyun Huang、Wei Yi
DOI:10.1021/acs.orglett.7b03546
日期:2018.1.5
Rhodium(III)- and iridium(III)-catalyzedC–H activation of oximes and coupling with propargyl alcohols is discussed. Depending on the catalyst, the reaction pathway switched between [3 + 2] and [4 + 2] annulations, thus giving divergent access to indenamines and isoquinolines in a one-pot and atom-economical manner. The hydroxyl group in the tertiary propargyl alcohol substrate was found to be crucial
Anthranil: An Aminating Reagent Leading to Bifunctionality for Both C(sp<sup>3</sup>)−H and C(sp<sup>2</sup>)−H under Rhodium(III) Catalysis
作者:Songjie Yu、Guodong Tang、Yingzi Li、Xukai Zhou、Yu Lan、Xingwei Li
DOI:10.1002/anie.201602224
日期:2016.7.18
nitrogenation suffered from simple amidation/amination with limited atom‐economy and is mostly limited to C(sp2)−H substrates. In this work, anthranil was designed as a novel bifunctional aminating reagent for both C(sp2)−H and C(sp3)−H bonds under rhodium(III) catalysis, thus affording a nucleophilic aniline tethered to an electrophilic carbonyl. A tridendate rhodium(III) complex has been isolated as the
Rhodium(III)-Catalyzed Synthesis of Cinnolinium Salts from Azobenzenes and Diazo Compounds
作者:Xiaohong Chen、Guangfan Zheng、Guoyong Song、Xingwei Li
DOI:10.1002/adsc.201800326
日期:2018.8.6
A Rh(III)‐catalyzed C−H activation of azobenzenes in the coupling with diazo compounds has been realized, providing a straightforward strategy to access functionalized cinnolinium triflates in high yields. This protocol features silver free mild reaction conditions and compatibility with diverse functional groups. The coupling proceeds via initial Rh(III)‐catalyzed C−H alkylation, followed by zinc
The Rh(III)-catalyzed amidation of C(sp2)-H bonds has been reported by employing the N-methoxyamide as a novel amino source. An excellent level of functional group tolerance can be achieved when N-methoxyamide derivatives are used as the amidating reagents. Importantly, several known bioactive compounds such as Aminalon, Pregabalin, Gabapentin, and Probenecid can be transformed to effective amidating
C(sp2)–H bond oxidation of oximes or azobenzenes with diverse carboxylic acids has been developed. In contrast to the previous catalytic systems, this protocol features mild conditions (close to room temperature for most cases) and a broad substrate scope (up to 64 examples), thus constituting a versatile method to directly prepare diverse O-aryl esters. Moreover, the superiority of the nitrate additive