A copper-mediatedsynthesis of 4-(trifluoromethyl)pyrazoles is described. In one step from readily accessible α,β-alkynic tosylhydrazones, a remarkable domino sequence of cyclization, trifluoromethylation, and detosylation takes place to furnish the 4-CF3N-H pyrazole cores with good functional group compatibility. The reaction conditions are mild and convenient, at room temperature in air, using the
描述了铜介导的4-(三氟甲基)吡唑的合成。从易于获得的α,β-炔基甲苯磺酰nes的一个步骤中,发生了显着的环化,三氟甲基化和脱甲苯基化的多米诺序列,为4-CF 3 N -H吡唑核提供了良好的官能团相容性。使用可商购的三氟甲基三甲基硅烷(TMSCF 3)作为CF 3源,在空气中于室温下,反应条件温和且方便。该方法可以应用于抗炎药塞来昔布的4-CF 3类似物的合成。
An effective preparation of both 1,3-diketones and nitriles from alkynones with oximes as hydroxide sources
An effective phosphine-catalyzed protocol has been established for the syntheses of 1,3-diketones and nitriles from alkynones with oximes as hydroxide surrogates. This method features the use of a phosphine catalyst, compatibility with various functional groups and ambient temperature, which makes this approach very practical. A plausible mechanism was proposed.
Base-Controlled Divergent Synthesis of 5-Cyanobenzoxepines and Benzofuro[2,3-<i>b</i>]pyridines from 2-Bromophenylacetonitriles and Ynones
作者:Lu-Lu Chen、Jing-Wen Zhang、Pei Chen、Shuai Zhang、Wan-Wan Yang、Ji-Ya Fu、Jun-Yan Zhu、Yan-Bo Wang
DOI:10.1021/acs.orglett.9b01700
日期:2019.7.19
2-bromophenylacetonitriles and ynones has been developed. Various functionalized 5-cyanobenzoxepines and benzofuro[2,3-b]pyridines were obtained with a broad substrate scope and high regioselectivity in moderate to excellent yield. Of importance, an unexpected O-rearrangement reaction to access benzofuro[2,3-b]pyridines was observed using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as the base, and the possible mechanism
已经开发出一种有效的碱控制的2-溴苯基乙腈和炔酮的发散环化反应。获得了各种官能化的5-氰基苯并pine庚因和苯并呋喃[2,3- b ]吡啶,它们具有较宽的底物范围和较高的区域选择性,且产率中等至优异。重要的是,使用1,8-二氮杂双环[5.4.0]十一碳-7-烯(DBU)作为碱,观察到了意外的O重排反应,可接近苯并呋喃[2,3- b ]吡啶。由18个O标记的实验支持。另外,研究了克级合成和产物的进一步转化。
Recyclable heterogeneous palladium-catalyzed carbonylative Sonogashira coupling under CO gas-free conditions
作者:Zebiao Zhou、Jianying Li、Zhaotao Xu、Mingzhong Cai
DOI:10.1080/00397911.2020.1762092
日期:2020.7.2
Abstract A convenient, efficient and practical heterogeneous palladium-catalyzed carbonylative Sonogashiracoupling of aryl iodides with terminal alkynes under CO gas-free conditions has been developed by using an MCM-41-supported bidentate phosphine palladium acetate complex as catalyst. Here, formic acid was used as the CO source with dicyclohexylcarbodiimide (DCC) as the activator and a wide variety
摘要 以MCM-41负载的双齿膦乙酸钯配合物为催化剂,开发了一种方便、高效、实用的多相钯催化羰基化Sonogashira偶联芳基碘与末端炔烃在无CO气体条件下的反应。在这里,甲酸用作 CO 源,二环己基碳二亚胺 (DCC) 作为活化剂,并以中等至高产率生成了多种炔基酮。这种多相钯催化剂可以通过简单的过滤过程轻松回收,最多可循环使用 8 次,而不会明显降低活性。图形概要
Iron(<scp>iii</scp>) chloride-promoted cyclization of α,β-alkynic tosylhydrazones with diselenides: synthesis of 4-(arylselanyl)-1<i>H</i>-pyrazoles
作者:Hai-Feng Yao、Fang-Hui Li、Jian Li、Shun-Yi Wang、Shun-Jun Ji
DOI:10.1039/d0ob00048e
日期:——
A highly efficient iron(iii) chloride-promoted cyclization between α,β-alkynic tosylhydrazones and diselenides to form a 4-(arylselanyl)-1H-pyrazole skeleton is studied.