Treatment of gamma-unsaturated oxime esters with cupric acetate or ferric chloride in acetic acid / t-butanol or in t-butanol alone leads to the formation of vinyl- or chloroalkyl- substituted Delta(1)-pyrrolines in moderate to good yield.
4-HO-TEMPO-Catalyzed Redox Annulation of Cyclopropanols with Oxime Acetates toward Pyridine Derivatives
作者:Jun-Long Zhan、Meng-Wei Wu、Dian Wei、Bang-Yi Wei、Yu Jiang、Wei Yu、Bing Han
DOI:10.1021/acscatal.9b00832
日期:2019.5.3
for the synthesis of pyridines through the annulation of cyclopropanols and oxime acetates has been developed. This protocol features good functional group tolerance and high chemoselectivity and also promises to be efficient for the late-stage functionalization of skeletons of drugs and natural products. Mechanism studies indicate that the reaction involves the in situ generated α,β-unsaturated ketones
Trichloroisocyanuric Acid Promoted Cascade Cyclization/Trifluoromethylation of Allylic Oximes: Synthesis of Trifluoromethylated Isoxazolines
作者:Weigang Zhang、Yingpeng Su、Ke-Hu Wang、Lili Wu、Bingbing Chang、Ya Shi、Danfeng Huang、Yulai Hu
DOI:10.1021/acs.orglett.6b03582
日期:2017.1.20
Cheap and commercially available trichloroisocyanuric acid has been used to promote trifluoromethylation by using TMSCF3 as the trifluoromethyl source. The method provides a novel and efficient protocol for the construction of CF3-containing 4,5-dihydroisoxazoles from allylic oximes in good to excellent yields.
Asymmetric imino-acylation of alkenes enabled by HAT-photo/nickel cocatalysis
作者:Rui Wang、Chuan Wang
DOI:10.1039/d3sc01945d
日期:——
By merging nickel-mediated facially selective aza-Heck cyclization and radical acyl C–Hactivation promoted by tetrabutylammonium decatungstate (TBADT) as a hydrogen atom transfer (HAT) photocatalyst, we accomplish an asymmetric imino-acylation of oxime ester-tethered alkenes with readily available aldehydes as the acyl source, enabling the synthesis of highly enantioenriched pyrrolines bearing an
通过将镍介导的表面选择性氮杂赫克环化和四丁基十钨酸铵(TBADT)作为氢原子转移(HAT)光催化剂促进的自由基酰基C-H活化相结合,我们可以轻松地实现肟酯系链烯烃的不对称亚氨基酰化。可用醛作为酰基源,能够在温和条件下合成带有酰基取代的立体中心的高度对映体富集的吡咯啉。初步机理研究支持 Ni( I )/Ni( II )/Ni( III ) 催化序列,涉及分子内迁移将束缚烯基单元插入 Ni( III )–N 键中作为对映体区分步骤。