在存在B(C 6 F 5)3 · n H 2 O(2摩尔%)的条件下,开发了水中无催化的α-重氮酸酯插入金属的O–H键,从而获得了一系列的α-羟基酯。好到极好的产量。该反应具有易于操作和广泛的底物范围的特点,重要的是,与常规方法相比,不需要金属。重要的是,这种方法进一步扩展了B(C 6 F 5)3在耐水条件下的应用。
<i>gem-</i>Difluoroolefination of Diazo Compounds with TMSCF<sub>3</sub> or TMSCF<sub>2</sub>Br: Transition-Metal-Free Cross-Coupling of Two Carbene Precursors
作者:Mingyou Hu、Chuanfa Ni、Lingchun Li、Yongxin Han、Jinbo Hu
DOI:10.1021/jacs.5b09888
日期:2015.11.18
fragment resulting from a diazocompound and a difluorocarbene fragment derived from Ruppert-Prakash reagent (TMSCF3) or TMSCF2Br, has been developed. This gem-difluoroolefination proceeds through the direct nucleophilic addition of diazocompounds to difluorocarbene followed by elimination of N2. Compared to previously reported Cu-catalyzed gem-difluoroolefination of diazocompounds with TMSCF3, which possesses
Copper-Mediated Trifluoromethylation of α-Diazo Esters with TMSCF<sub>3</sub>: The Important Role of Water as a Promoter
作者:Mingyou Hu、Chuanfa Ni、Jinbo Hu
DOI:10.1021/ja307058c
日期:2012.9.19
Copper-mediatedtrifluoromethylation of α-diazo esters with TMSCF(3) reagent has been developed as a new method to prepare α-trifluoromethyl esters. This trifluoromethylation reaction represents the first example of fluoroalkylation of a non-fluorinated carbene precursor. Water plays an important role in promoting the reaction by activating the "CuCF(3)" species prepared from CuI/TMSCF(3)/CsF (1.0:1
Amination of Diazocarbonyl Compounds: N–H Insertion under Metal-Free Conditions
作者:Xuesong Luo、Gui Chen、Lin He、Xueliang Huang
DOI:10.1021/acs.joc.6b00233
日期:2016.4.1
Transition-metal-free intermolecular N–H insertion of α-diazocarbonyl compounds is reported. Among the series of nitrogen sources examined, dibenzenesulfonimide was found to be the choice in terms of the yields and the reaction time. Primary mechanistic experiments suggest that a pathway involving a sequence of protonation and nucleophilic substitution was preferred.
Copper-Mediated Deuterotrifluoromethylation of <i>α</i>
?Diazo Esters
作者:Mingyou Hu、Qiqiang Xie、Xinjin Li、Chuanfa Ni、Jinbo Hu
DOI:10.1002/cjoc.201600004
日期:2016.5
ation of α?diazo esters under the promotion of deuterium oxide (D2O) has been developed for the synthesis of deuterium‐labeled trifluoromethyl compounds. This deuterotrifluoromethylation reaction is of broad scope and can afford the deuterated products with higher than 99% isotopic purity. Moreover, the results of this investigation also provide some experimental evidences to support our previously
A challenging metal-free azide insertion of α-aryl α-diazoesters in the presence of B(C6F5)3 (5 mol %) was developed for the first time. The reaction features an easy operation, wide substrate scope, and mild conditions and affords the corresponding products in moderate to high yields. More importantly, alkene and alkyne functional groups were well tolerated because no cyclopropanation or cyclopropenation
首次开发了在B(C 6 F 5)3(5 mol%)存在下具有挑战性的无金属的α-芳基α-重氮酸酯叠氮化物插入物。该反应具有易于操作,底物范围宽和条件温和的特点,并以中等至高收率提供了相应的产物。更重要的是,由于未观察到环丙烷化或环丙烷化,因此对烯烃和炔烃官能团的耐受性良好。此外,在简单转化后,相应的叠氮化物产物可以转化为伯胺或1,2,3-三唑衍生物。