Applications of C–H Functionalization Logic to Cyclobutane Synthesis
摘要:
The application of C-H functionalization logic to target-oriented synthesis provides an exciting new venue for the development of new and useful strategies in organic chemistry. In this article, C-H functionalization reactions are explored as an alternative approach to access pseudodimeric cyclobutane natural products, such as the dictazole and the piperarborenine families. The use of these strategies in a variety of complex settings highlights the subtle geometric, steric, and electronic effects at play in the auxiliary guided C-H fimctionalization of cyclobutanes.
Tetracoordinate borates as catalysts for reductive formylation of amines with carbon dioxide
作者:Xiaolin Jiang、Zijun Huang、Mohamed Makha、Chen-Xia Du、Dongmei Zhao、Fang Wang、Yuehui Li
DOI:10.1039/d0gc01741h
日期:——
We report sodium trihydroxyaryl borates as the first robust tetracoordinate organoboron catalysts for reductive functionalization of CO2. These catalysts, easily synthesized from condensing boronic acids with metal hydroxides, activate main group element–hydrogen (E–H) bonds efficiently. In contrast to BX3 type boranes, boronic acids and metal-BAr4 salts, under transition metal-free conditions, sodium
Abstract We report transamidation protocol to synthesize a range of secondary and tertiary amides from weakly nucleophilic aromatic and hetero-aryl amines with low reactive formamide derivatives, utilizing hydrochloric acid as catalyst. This current acid mediated strategy is beneficial because it eliminates the need for a metal catalyst, promoter or additives in the reaction, simplifies isolation and
KO<sup><i>t</i></sup>Bu-Promoted Transition-Metal-Free Transamidation of Primary and Tertiary Amides with Amines
作者:Tridev Ghosh、Snehasish Jana、Jyotirmayee Dash
DOI:10.1021/acs.orglett.9b02306
日期:2019.9.6
transamidation of primary and tertiary amides with a range of aryl, heteroaryl, and aliphatic amines using potassium tert-butoxide. The reaction proceeds at roomtemperature under transition-metal-free conditions providing secondary amides in high yields. Moreover, reaction of cyclopropyl amine with tertiary amides proceeds with ring-opening to provide a rapid access to enamides.
Copper‐Catalyzed Formylation of Amines by using Methanol as the C1 Source
作者:Manuel Carmona Pichardo、Ghazal Tavakoli、Jessica E. Armstrong、Tobias Wilczek、Bradley E. Thomas、Martin H. G. Prechtl
DOI:10.1002/cssc.201903266
日期:2020.3.9
coupling of alcohols and amines to imines under oxidative conditions. In this study, such a Cu/TEMPO catalyst system is found to catalyze the N-formylation of a variety of amines by initial oxidative activation of methanol as the carbonyl source via formaldehyde and formation of N,O-hemiacetals and oxidation of the latter under very mild conditions. A vast range of amines, including aromatic and aliphatic
Catalyst-Free Transamidation of Aromatic Amines with Formamide Derivatives and Tertiary Amides with Aliphatic Amines
作者:Jiawen Yin、Jingyu Zhang、Changqun Cai、Guo-Jun Deng、Hang Gong
DOI:10.1021/acs.orglett.8b03542
日期:2019.1.18
A simple catalyst- and promoter-free protocol has been developed for the transamidation of weakly nucleophilic aromatic amines with formamide derivatives and low-reactivity tertiary amides with aliphatic amines. This strategy is advantageous because no catalyst or promoters are needed, no additives are required, separation and purification is easy, and the reaction is scalable. Significantly, this