Visible-Light Photoredox Catalyzed Three-Component Cyclization of 2H-Azirines, Alkynyl Bromides, and Molecular Oxygen to Oxazole Skeleton
摘要:
A novel three-component cyclization of 2H-azirines, alkynyl bromides, and molecular oxygen under visible light photoredox catalysis at room temperature has been developed, which provides a direct approach to a wide range of substituted oxazoles in moderate to good yields.
Self-Catalyzed Rapid Synthesis of <i>N</i>-Acylated/<i>N</i>-Formylated α-Aminoketones and <i>N</i>-Hydroxymethylated Formamides from 3-Aryl-2<i>H</i>-Azirines and 2-Me/Ph-3-Aryl-2<i>H</i>-Azirines
作者:Aramita De、Sougata Santra、Grigory V. Zyryanov、Adinath Majee
DOI:10.1021/acs.orglett.0c01206
日期:2020.5.15
by the reaction of 3-aryl-2H-azirines and highly substituted 2-Me/Ph-3-aryl-2H-azirines with various carboxylic acids under ambient air within 10 min at room temperature. N-Trifluoroacetylated α-aminoketones with different substituents have been reported in the presence of trifluoroacetic acid. This protocol is equally effective to synthesize N-formylated α-aminoketone and N-hydroxymethylated formamide
Selective C–C bond formation from rhodium-catalyzed C–H activation reaction of 2-arylpyridines with 3-aryl-2<i>H</i>-azirines
作者:Yonghyeon Baek、Jinwoo Kim、Hyunseok Kim Hyunseok Kim、Seung Jin Jung、Ho Ryu、Suyeon Kim、Jeong-Yu Son、Kyusik Um、Sang Hoon Han、Hyung Jin Seo、Juyoung Heo、Kooyeon Lee、Mu-Hyun Baik、Phil Ho Lee
DOI:10.1039/c8sc05142a
日期:——
coupling. Computational studies quickly revealed and prototype experimental work confirmed that neither the formation of the expected metal nitrene complexes nor the C–N coupling were viable. Instead, azirine ring-opening followed by C–C coupling was found to be much more favorable to give imines that readily underwent hydrolysis in aqueous conditions to form acylmethyl-substituted products. This new method
Cu/Ag-Catalyzed Reaction of Azirines with Anthranils: Synthesis of (Quinazolin-2-yl)methanone Derivatives
作者:Yajun Sun、Huimin Sun、Ying Wang、Fang Xie
DOI:10.1021/acs.orglett.0c02222
日期:2020.9.4
to expedite syntheses of (quinazolin2-yl)methanone derivatives. The transformation represents an unprecedented approach which employs a copper catalysis to cleave both a N–C2 azirine bond and N–O anthranil bond. Subsequently, an unexplored 1,3-hydroxyl migration and β-N elimination are likely the key to access (quinazolin-2-yl)methanone derivatives.
Cu / Ag催化3-芳基2 H-叠氮基与蒽的环化反应已加快了(quinazolin2-yl)methanone衍生物的合成。该转变代表了一种空前的方法,该方法采用铜催化来裂解N–C 2叠氮键和N–O蒽键。随后,未经探索的1,3-羟基迁移和β-N消除可能是获得(喹唑啉-2-基)甲酮衍生物的关键。
Ligand- and Substrate-Controlled Chemodivergent Pd-Catalyzed Annulations of Cyclic β-Keto Esters with 3-Aryl-2<i>H</i>-azirines
Chemodivergent Pd-catalyzed annulations of cyclic β-keto esters with 3-aryl-2H-azirines have been developed to provide rapid access to eight-membered ringlactams, bicyclic 3,4-dihydro-2H-pyrrole derivatives, and (E)-methyl [2-(2-oxocyclohexylidene)-2-phenylethyl]carbamates with high efficiency. The chemoselectivity can be determined by tuning the mono- or bisphosphine ligands as well as the substrate
Cu-Catalyzed Ring Opening Reaction of 2<i>H</i>-Azirines with Terminal Alkynes: An Easy Access to 3-Alkynylated Pyrroles
作者:Tengfei Li、Xiaoyi Xin、Chunxiang Wang、Dongping Wang、Fan Wu、Xincheng Li、Boshun Wan
DOI:10.1021/ol502282j
日期:2014.9.19
A highly efficient Cu-catalyzed ring expansion reaction of 2H-azirines with terminal alkynes has been developed. This transformation provides a powerful method for the synthesis of 3-alkynyl polysubstituted pyrroles under mild conditions in good yields. The direct transformation process, specific selectivity, and good tolerance to a variety of substituents make it an alternative approach to the reported protocols.