Direct Conversion of Indoles to 3,3-Difluoro-2-oxindoles via Electrophilic Fluorination
摘要:
3,3-Difluoro-2-oxindoles can be obtained directly from indoles in moderate yields via electrophilic fluorination using N-fluorobenzenesulfonimide as a mild fluorinating reagent. The presence of tell-butyl hydroperoxide during the reaction, together with additional heating after quenching the reaction with triethylamine, is beneficial to the formation of the desired product.
The ligand-free palladium-catalyzed C3-cyanation of indoles via direct C–H functionalization was achieved. This protocol, utilizing CH3CN as a green and readily available cyanide source, produced the desired products in moderate to good yields through transition-metal-catalyzed C–CN bond cleavage.
Expedient Synthesis of <i>N</i>-Acyl Anthranilamides and β-Enamine Amides by the Rh(III)-Catalyzed Amidation of Aryl and Vinyl C–H Bonds with Isocyanates
作者:Kevin D. Hesp、Robert G. Bergman、Jonathan A. Ellman
DOI:10.1021/ja203495c
日期:2011.8.3
A Rh(III)-catalyzed protocol for the amidation of anilide and enamide C-H bonds with isocyanates has been developed. This method provides direct and efficient syntheses of N-acyl anthranilamides, enamine amides, and pyrimidin-4-one heterocycles.
Chiral Macrocycle‐Enabled Counteranion Trapping for Boosting Highly Efficient and Enantioselective Catalysis
作者:Rui Ning、Hao Zhou、Shi‐Xin Nie、Yu‐Fei Ao、De‐Xian Wang、Qi‐Qiang Wang
DOI:10.1002/anie.202003673
日期:2020.6.26
manipulated for tuning the catalysis process. In parallel to well‐developed crown ether‐based cation‐binding catalysis, a macrocycle‐enabled counteranion trapping strategy is presented for boosting highly efficient and enantioselective catalysis. A set of bis‐diarylthiourea macrocycles containing two BINOL moieties were designed and synthesized. They possess a well‐confined chiral cavity and strong binding
A palladium-catalyzed difluoromethylation of a series of heteroaryl chlorides, bromides and iodides under mild conditions is described. A wide range of heteroaryl halides such as pyridyl, pyrimidyl, pyrazyl, funanyl, thienyl, pyazolyl, imidazolyl, thiazolyl, and oxazolyl halides were efficiently difluoromethylated, thus providing medicinal chemists an alternative choice for the preparation of drug
Synthesis of Tetracyclic Indoles via Intramolecular α-Arylation of Ketones
作者:Malik Hellal、Shambhavi Singh、Gregory D. Cuny
DOI:10.1021/jo300052z
日期:2012.4.20
An intramolecular palladium(0)-mediated α-arylation of ketones applied to the synthesis of various substituted tetracyclic indoles is reported. Most significantly, the efficiency of the transformation was enhanced by the use of monoligated Pd(0) complexes. This methodology was extended to double α-arylation of ketones using one-pot reactions with either simultaneous addition or sequential addition