Nitromethane as a Carbanion Source for Domino Benzoannulation with Ynones: One‐Pot Synthesis of Polyfunctional Naphthalenes and a Total Synthesis of Macarpine
applicability has been devised for the regioselective synthesis of polyfunctional naphthalenes by employing nitromethane and ortho‐haloaryl ynones. Utilization of nitromethane as a one carbon carbanion source that is incorporated into a variety of ynones, ends up as an aromatic nitro substituent. The application of this domino process towards a total synthesis of the polycyclic alkaloid macarpine demonstrate
的单釜,过渡金属-自由,多米诺迈克尔/ S Ñ普遍适用性的Ar协议已经通过使用硝基甲烷和设计用于多官能萘的区域选择性合成邻-haloaryl ynones。硝基甲烷作为一种碳碳负离子源的使用,并被引入到各种炔酮中,最终以芳族硝基取代基的形式出现。该多米诺法在多环生物碱马卡平的全合成中的应用证明了该方法的有效性。在概念上是简单的方法来影响ynones显示广泛的底物范围和官能团耐受性,并已与被取代的硝基甲烷实现的区域选择性,多功能benzoannulation以及与脂环ö-单倍体。
Stereoselective Michael-Aldol Tandem Reaction of Diorganyl Diselenides or Diorganyl Disulfides with Conjugate Alkynones Mediated by Samarium Diiodide
作者:Yongmin Zhang、Xingliang Zheng、Xiaoliang Xu
DOI:10.1055/s-2003-41489
日期:——
Stereoselective Michael addition and Michael-aldol tandem reaction of diorganyl diselenides and diorganyl disulfides with conjugate alkynones mediated by samarium diiodide were studied. The reaction temperature was a dominating factor for the stereoselectivity. β-Organylselenoalkenones or β-organylthioalkenones and γ-organylselenoallylic alcohols or γ-organylthioallylic alcohols were prepared in good yields.
Zheng, Xingliang; Zhang, Yongmin, Journal of Chemical Research, 2004, # 6, p. 412 - 413
作者:Zheng, Xingliang、Zhang, Yongmin
DOI:——
日期:——
Combining Electronic and Steric Effects To Generate Hindered Propargylic Alcohols in High Enantiomeric Excess
作者:Vijyesh K. Vyas、Richard C. Knighton、Bhalchandra M. Bhanage、Martin Wills
DOI:10.1021/acs.orglett.7b03884
日期:2018.2.16
o-fluoro substituents results in an improvement to the reduction enantioselectivity, as does the replacement of a phenyl ring on the alkyne with a trimethylsilyl group. These effects are rationalized as resulting from a change in the steric properties of the aryl ring and the electronic properties of the alkyne which, when matched in the reduction transition state, combine within a “window” of substrate/catalyst