Exploration of Biaryl Carboxylic Acids as Proton Shuttles for the Selective Functionalization of Indole C–H Bonds
摘要:
A survey of diversely substituted 2-arylbenzoic acids were synthesized and tested for use as proton shuttle in the direct arylation of indoles with bromobenzenes. It was found that 3-ethoxy-2-phenylbenzoic acid gives superior yield and selectivity for this class of substrates.
photocatalytic aerobicoxidative lactonization of arene C(sp2)–H bonds proceeds in the presence of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and tert-butyl nitrite (TBN). Under the optimized conditions, a range of 2-arylbenzoic acids is converted into the corresponding benzocoumarin derivatives in moderate to excellent yields. This method is characterized by its atom economy, mild reaction conditions, the
Vitamin Catalysis: Direct, Photocatalytic Synthesis of Benzocoumarins via (−)-Riboflavin-Mediated Electron Transfer
作者:Tobias Morack、Jan B. Metternich、Ryan Gilmour
DOI:10.1021/acs.orglett.8b00052
日期:2018.3.2
photoactivated (−)-riboflavin (vitamin B2) to generate the heterocyclic core via photoinduced single electron transfer. Collectively, the inexpensive nature of the catalyst, ease of execution, and absence of external metal additives are a convincing endorsement for the incorporation of simple vitamins in contemporary catalysis.
Iodobenzene-Catalyzed Synthesis of Phenanthridinones via Oxidative C–H Amidation
作者:Dongdong Liang、Wenbo Yu、Nam Nguyen、Jeffrey R. Deschamps、Gregory H. Imler、Yue Li、Alexander D. MacKerell、Chao Jiang、Fengtian Xue
DOI:10.1021/acs.joc.7b00106
日期:2017.4.7
synthesis of phenanthridinones from N-methoxybenzamides using an oxidative C–H amidation reaction at room temperature in open air with modest to excellent yields. This method demonstrated unprecedented substrate scope. In particular, it solved the long-standing challenge in the synthesis of phenanthridinones with stericallydemanding substitutions.
a transition metal, is described using a novel partner in the Suzuki–Miyaura couplingreaction catalyzed by Pd(OAc)2 and Ruphos as ligands. The products showed good to outstanding yields and broad functional group compatibility under optimal conditions. The sequentialsynthesis of non-symmetric terphenyls and the gram grade process highlight the approach's synthetic utility. DFT calculations have shown
LiCl-Accelerated Multimetallic Cross-Coupling of Aryl Chlorides with Aryl Triflates
作者:Liangbin Huang、Laura K. G. Ackerman、Kai Kang、Astrid M. Parsons、Daniel J. Weix
DOI:10.1021/jacs.9b05461
日期:2019.7.17
While the synthesis of biaryls has advanced rapidly in the past decades, cross-Ullman couplings of arylchlorides, the most abundant aryl electrophiles, have remained elusive. Reported here is the first general cross-Ullman coupling of arylchlorides with aryl triflates. The selectivity challenge associated with coupling an inert electrophile with a reactive one is overcome using a multimetallic strategy