A simple protocol of manganese catalyzed selective α-alkenylation of ketones using primary alcohols is reported. The reactions proceeded well with a low loading of catalyst (0.3 mol %). The overall transformation operates through O–H bond activation of primary alcohols via dearomatization–aromatization metal ligand cooperation in the catalyst to provide the corresponding aldehydes, which further undergo
Synthesis of Benzo[<i>c</i>]xanthones from 2-Benzylidene-1-tetralones by the Ultraviolet Radiation-Mediated Tandem Reaction
作者:Wen-Zhi Xu、Zhi-Tang Huang、Qi-Yu Zheng
DOI:10.1021/jo8008929
日期:2008.7.1
A facile one-pot method to prepare benzo[c]xanthones from readily accessible benzylidene-1-tetralones by the ultraviolet radiation-mediated tandemreaction is reported. The overall transformation presumably involves cis−trans isomerization, oxa-6π electrocyclization, singlet oxygen ene reaction, dehydration, and aromatization.
报道了一种容易的一锅法,该方法通过紫外线介导的串联反应从容易获得的亚苄基-1-四氢萘酮制备苯并[ c ]氧杂蒽。整个转化可能涉及顺反异构化,oxa-6π电环化,单线态氧烯反应,脱水和芳构化。
Facile Synthesis of Functional Tricyclic Fused Furans by Intramolecular Wittig Reactions
作者:Yi-Ling Tsai、Utpal Das、Siang-en Syu、Chia-Jui Lee、Wenwei Lin
DOI:10.1002/ejoc.201300426
日期:2013.7
the preparation of tricyclic fused furans in one step starting from acid chlorides and Michael acceptors is described. The reaction conditions are mild, operationally simple, and have a broad substrate scope. The reaction is believed to proceed by an intramolecular Wittigreaction with a phosphorus ylide as the key intermediate.
Ru-catalyzed asymmetric hydrogenation of α,β-unsaturated ketones via a hydrogenation/isomerization cascade
作者:Kun Wang、Saisai Niu、Weijun Tang、Dong Xue、Jianliang Xiao、Hongfeng Li、Chao Wang
DOI:10.1039/d4cc00356j
日期:——
Ru-catalyzed asymmetric hydrogenation of α-substituted α,β-unsaturatedketones has been developed for the enantioselective synthesis of chiral α-substituted secondary alcohols with high diastereo- and enantioselectivities (up to >99 : 1 dr, 98% ee). Mechanistic experiments suggest that the reaction proceeds via a Ru-catalyzed asymmetric hydrogenation of the CO bond in concert with a base-promoted allylic