SmI<sub>2</sub>-mediated reductive cyclization of β-arylthio ketones: a facile and diastereoselective synthesis of thiochroman derivatives
作者:Hui Mao、Bing-Xin You、Lie-Jin Zhou、Ting-Ting Xie、Yi-Hang Wen、Xin Lv、Xiao-Xia Wang
DOI:10.1039/c7ob01082f
日期:——
SmI2-mediated reductive cyclization of β-arylthio ketones to generate thiochroman derivatives is not generally observed process and the reported examples are limited to geminal disubstitution in the substrates. The results of the current study show that the cyclization also occurs when other substitution patterns are present, affording a general approach to dihydrothiochroman-ols in good yields and
Metal-free and highly regioselective synthesis of N-heteroaryl substituted pyrazoles from α,β-unsaturated N-tosylhydrazones and heteroaryl chlorides
作者:Lin Zeng、Xiao-Qiang Guo、Zai-Jun Yang、Ya Gan、Lian-Mei Chen、Tai-Ran Kang
DOI:10.1016/j.tetlet.2019.07.034
日期:2019.8
β-unsaturated N-tosylhydrazones with N-heteroaryl chlorides was developed for the synthesis of N-heteroaryl pyrazole derivatives. This one-pot reaction provided bi(heteroaryl) derivatives in good to excellent yields and with excellent regioselectivity. The procedure is operationally simple and applicable to large-scale synthesis.
Organocatalytic diastereo- and enantioselective oxa-hetero-Diels–Alder reactions of enones with aryl trifluoromethyl ketones for the synthesis of trifluoromethyl-substituted tetrahydropyrans
作者:Maira Pasha、Fujie Tanaka
DOI:10.1039/d1ob01844b
日期:——
high diastereo- and enantioselectivities. Mechanistic investigation suggested that the reactions involve a [4 + 2] cycloaddition pathway, in which the enamine of the enone acts as the diene and the ketone carbonyl group of the aryl trifluoromethylketone acts as the dienophile. In this study, tetrahydropyran derivatives with the desired stereochemistry that are difficult to synthesize by previously reported
Highly Diastereo- and Enantioselective Cross-Cascade Reactions of Different Enones
作者:Huicai Huang、Wenbin Wu、Kailong Zhu、Juan Hu、Jinxing Ye
DOI:10.1002/chem.201204520
日期:2013.3.18
Cascading ketones! The first highly efficient asymmetric cross‐cascade reaction of different α,β‐unsaturated ketones catalyzed by an easily prepared bulky primary amine salt has been developed. It affords the corresponding diverse products containing three to four contiguous stereocenters with excellent enantio‐ and diastereoselectivities (see scheme).
A Rh(III)-catalyzed enaminone-directed alkenyl C–H coupling with alkynes for the synthesis of salicylaldehyde derivatives is reported. This represents a unique example of benzene ring framework formation through a transition-metal-catalyzed, directed C–Hactivation strategy. The two incorporated reactive functionalities, aldehyde and hydroxy groups, provide convenient synthetic handles for further