开发了一种在无催化剂条件下,α-重氮酮与二苯并[ b , f ][1,4]氧氮杂/硫氮杂亚胺之间有效可见光诱导的施陶丁格[2+2]成环反应。该方案提供了一种简便的方法来合成具有季碳中心的四环二苯并[ b,f ][1,4]氧氮杂/硫氮杂稠合β-内酰胺,具有广泛的底物范围和高效率(37个例子,高达>99%屈服)。
Pd(0)-catalyzed cross-coupling of allyl halides with α-diazocarbonyl compounds or N-mesylhydrazones: synthesis of 1,3-diene compounds
作者:Kang Wang、Shufeng Chen、Hang Zhang、Shuai Xu、Fei Ye、Yan Zhang、Jianbo Wang
DOI:10.1039/c6ob00454g
日期:——
With palladiumcatalysis, allyl bromides or chlorides react with α-diazocarbonyl compounds or N-mesylhydrazones to afford 1,3-diene derivatives. The reaction represents a novel and efficient method for the synthesis of 1,3-butadiene derivatives. Mechanistically, the reaction is proposed to follow a pathway involving the formation of a π-allylic palladium carbene complex and subsequent migratory insertion
Palladium-catalyzed reaction of allyl halides with α-diazocarbonyl compounds
作者:Shufeng Chen、Jianbo Wang
DOI:10.1039/b806970k
日期:——
The Pd(OAc)(2)-catalyzed reaction between alpha-diazocarbonyl compounds and allyl bromides or chlorides leads to the formation of 1,3-diene derivatives.
Synthesis of hydroindoles <i>via</i> desymmetric [3+2] cycloadditions of <i>para</i>-quinamines with photogenerated ketenes
作者:Dan Liu、Bin Shi、Hao Jiang、Ying Cheng、Wen-Jing Xiao、Liang-Qiu Lu
DOI:10.1039/d1cc03352b
日期:——
A DBU-catalyzed desymmetric [3+2] cycloaddition between para-quinamines and photogenerated ketenes was developed for the first time. Under the irradiation of low-energy blue LEDs, a variety of hydroindoles bearing all-carbon quaternary centers were produced with good reaction efficiency and complete diastereoselectivity (34 examples, 45–99% yields and >95 : 5 dr). This protocol represents a new approach
enynamides and α-diazoketones to produce chiral bicyclic lactams bearing chiral all-carbon quaternary stereocenters is realized with up to 95% yield, 98% ee, and >19:1 dr. The combination of visible light photoactivation and the relay of gold and N-oxide catalysis in a cascade process enabled the facile generation and controlled assembly of two reactive intermediates, ketene and aza-o-quinone methide
Herein, a visible-light-induced chiral N-heterocyclic carbene (NHC) catalyzed asymmetric amination of ketenes has been developed. This strategy provides a facile synthetic protocol for the efficient construction of α-chiral amides.