Metal-Free Iodosulfonylation of Internal Alkynes: Stereodefined Access to Tetrasubstituted Olefins
作者:Ravi Kumar、Vikas Dwivedi、Maddi Sridhar Reddy
DOI:10.1002/adsc.201700576
日期:2017.8.17
The stereoselective E‐iodosulfonylation of internalalkynes for synthesizing highly defined tetrasubstituted olefins using sodium phenyl sulfinate and iodine has been achieved. Most of the alkynes explored are non‐symmetrical and the regioselection is under full control. Arylalkynes with various electron‐withdrawing groups like keto, aldehyde, ester, amide, cyano, sulfone, bromo, chloro and iodo on
Regiocontrolled synthesis of 2,4,6-triarylpyridines from methyl ketones, electron-deficient acetylenes and ammonium acetate
作者:Dmitrii A. Shabalin、Marina Yu. Dvorko、Elena Yu. Schmidt、Boris A. Trofimov
DOI:10.1039/d1ob00193k
日期:——
A novel one-pot two-step approach for the synthesis of 2,4,6-triarylpyridines via t-BuOK/DMSO-promoted C-vinylation of a variety of methyl ketones with electron-deficient acetylenes (alkynones) followed by a cyclization of the in situ generated unsaturated 1,5-dicarbonyl species with ammonium acetate has been developed. This approach possesses competitive advantages such as high regioselectivity, available
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。
Synthesis of α,β-alkynyl ketones <i>via</i> the nickel catalysed carbonylative Sonogashira reaction using oxalic acid as a sustainable C1 source
作者:Shaifali Shaifali、Shankar Ram、Vandna Thakur、Pralay Das
DOI:10.1039/c9ob01064e
日期:——
An efficient and economic nickel-dppb catalyzed, carbonylative Sonogashira cross-coupling reaction was demonstrated to providerapidaccess to various α,β-alkynyl ketones from aryl iodides and terminal alkynes using oxalic acid as the ex situ C1 source in a double vial (DV) system. Notably, the role of the ligand in combination with the Ni catalyst for the selective formation of carbonylative Sonogashira
incompatibility of reaction conditions, when carbon dioxide was utilized as carbonyl source. Herein, a practical one-pot protocol using carbon dioxide as the carbonyl source for the palladium-catalyzed carbonylative Sonogashira coupling has been established, providing an expedient and practical route to a wide range of functionalized alkynones and indoxyls under mild reaction conditions. By finding a suitable
在过去的几年中,羰基化偶联反应已成为现代合成化学中构建含羰基化合物的强大而通用的策略。二氧化碳是一种可再生的单碳分子,近年来与二氧化碳相比,由于其丰度高、无毒和稳定性好,已成为最具吸引力和前景的羰基替代来源之一。然而,在大多数情况下,当二氧化碳被用作羰基源时,由于反应条件的复杂性和不相容性,通常需要双室技术来使产生 CO 和消耗 CO 的过程成功进行。在此,已经建立了使用二氧化碳作为钯催化羰基化 Sonogashira 偶联的羰基源的实用一锅方案,在温和的反应条件下为广泛的官能化炔酮和吲哚醇提供了一种方便实用的途径。通过找到合适的催化系统,该方法允许产生 CO 和消耗 CO 的过程在一个锅中进行,其中在没有任何氟化物试剂的情况下通过还原二氧化碳原位产生一氧化碳。该方法具有操作简单安全、底物易得、官能团耐受性好、反应条件温和等特点。其中一氧化碳是在没有任何氟化物试剂的情况下由二氧化碳的还原原