Organocatalytic cycloaddition of carbonyl sulfide with propargylic alcohols to 1,3-oxathiolan-2-ones
作者:Hui Zhou、Rui Zhang、Hui Zhang、Sen Mu、Xiao-Bing Lu
DOI:10.1039/c9cy00062c
日期:——
adducts of a Lewis base (LB) were synthesized and first used to catalyze the cycloaddition of COS with propargylic alcohols under mild reaction conditions, selectively providing the functionalized 1,3-oxathiolane-2-ones with complete (Z) configuration selectivity. Among them, COS adducts of highly polarized olefins proved to be highly efficientorganocatalysts for this transformation, with excellent yields
Über die cis, trans-isomeren 4-Phenyl-buten-(3)-one-(2) und 3-Phenyl-propen-(2)-ale-(1)
作者:G. Gamboni、V. Theus、H. Schinz
DOI:10.1002/hlca.19550380130
日期:——
Cis-4-Phenyl-buten-(3)-on-(2) und cis-3-Phenyl-propen-(2)-al-(1) wurden mit den schon bekannten entsprechenden trans-Verbindungen verglichen. Die beiden cis-Verbindungen sieden 12 bzw. 15° tiefer als die trans-Verbindungen. Sie sind ferner sehr säureempfindlich. Das cis-4-Phenyl-buten-(3)-on-(2) ist gegen Alkali beständig. Die beiden cis- und trans-Produkte wurden durch die Semicarbazone, Phenyl-semicarbazone
An environmentally benign protocol that affords propargylic sulfones containing highly congested carbon centers from easily accessible alcohols and sulfinic acids with water as the only byproduct is reported. The reaction proceeded via an in situ dehydrative cross-coupling process by taking advantage of the synergetic actions of multiple hydrogen bonds rather than relying on an external catalyst and/or
作者:Saswata Gupta、Siyuan Su、Yu Zhang、Peng Liu、Donald J. Wink、Daesung Lee
DOI:10.1021/jacs.1c02237
日期:2021.5.19
demonstrated them as an aromatic equivalent of the Grubbs-type ruthenium alkylidene catalysts. These ruthenabenzenes can be prepared via an enyne metathesis and metallotropic [1,3]-shift cascade process to form alkyne-chelated ruthenium alkylidene intermediates followed by spontaneous cycloaromatization. The aromatic nature of these complexes was confirmed by spectroscopic and X-ray crystallographic data
金属芳烃构成了一类独特的芳族化合物,其中一种或多种过渡金属元素结合到芳族体系中,其母体是金属苯。与碳原型相比,金属苯的主要关注点之一通常涉及与其相对芳香性相关的结构特征。含过渡金属的金属苯也涉及某些催化过程,例如炔烃复分解聚合;然而,这些基于过渡金属的金属芳族化合物尚未开发为催化剂。在此,我们描述了一种生成多种钌苯的有效策略,并将它们证明为 Grubbs 型钌亚烷基催化剂的芳族等价物。这些钌苯可以通过烯炔复分解和金属化[1,3]-移位级联工艺制备,形成炔烃螯合的亚烷基钌中间体,然后自发环芳构化。这些配合物的芳香性质通过光谱和 X 射线晶体学数据得到证实,并通过 DFT 计算研究了环芳构化过程的机理途径。这些钌苯对复分解和其他转化表现出强大的催化活性,这说明金属苯不仅是具有结构和理论意义的化合物,而且还是开发新催化剂的新平台。这些配合物的芳香性质通过光谱和 X 射线晶体学数据得到证实,并通过
Copper-Catalyzed Cascade Aminoalkynylation–Oxidation of Propargylic Alcohols: Stereospecific Synthesis of (<i>Z</i>)-2-Amino Conjugated Enynals/Enynones
Copper-catalyzed cascade aminoalkynylation–oxidation of propargylic alcohols has been realized, sterospecifically providing an array of (Z)-2-amino conjugated enynals/enynones in good yields under mild conditions. This transformation involves a rare 1,3-alkynyl migration of propargylic alcohols and simultaneously forms C–C, C–N, and C═O bonds. Furthermore, (Z)-2-amino conjugated enynals were applied