Zwitterionic analogs of cimetidine as H2 receptor antagonists
摘要:
A series of analogues of the H2 receptor histamine antagonist cimetidine have been synthesized in which the dipolar cyanoguanidine group has been replaced by a number of zwitterionic moieties. Although none of the compounds is more effective than cimetidine in blocking histamine-stimulated tachycardia on the isolated guinea pig atrium, the activities of most of the compounds possessing rigid dipoles can be accounted for on the basis of dipole orientation relative to the common side chain and by considering the active species in each case to be the zwitterion. These findings are in general agreement with those found for analogues having conjugated groups as dipoles.
Sequential C–H activation enabled expedient delivery of polyfunctional arenes
作者:Wensen Ouyang、Xiaoqing Cai、Xiaojian Chen、Jie Wang、Jianhang Rao、Yang Gao、Yanping Huo、Qian Chen、Xianwei Li
DOI:10.1039/d1cc03243g
日期:——
Modularconstruction of polyfunctional arenes from abundant feedstocks stands as an unremitting pursue in synthetic chemistry, accelerating the discovery of drugs and materials. Herein, using the multiple C–H activation strategy with versatile imidate esters, the expedient delivery of molecular libraries of densely functionalized sulfur-containing arenes was achieved, which enabled the concise construction
Synthesis of 1<i>H</i>-Indazoles from Imidates and Nitrosobenzenes via Synergistic Rhodium/Copper Catalysis
作者:Qiang Wang、Xingwei Li
DOI:10.1021/acs.orglett.6b00727
日期:2016.5.6
Nitrosobenzenes have been used as a convenient aminating reagent for the efficient synthesis of 1H-indazoles via rhodium and copper catalyzed C–H activation and C–N/N–N coupling. The reaction occurred under redox-neutral conditions with high efficiency and functional group tolerance. Moreover, a rhodacyclic imidate complex has been identified as a key intermediate.
Rh(III)-Catalyzed C–C/C–N Coupling of Imidates with α-Diazo Imidamide: Synthesis of Isoquinoline-Fused Indoles
作者:He Wang、Lei Li、Songjie Yu、Yunyun Li、Xingwei Li
DOI:10.1021/acs.orglett.6b01284
日期:2016.6.17
Imidate esters and diazo compounds have been established as bifunctional substrates for the construction of biologically active fused heterocycles viarhodium-catalyzed C–H activation and C–C/C–N coupling. This reaction occurs undermildconditions with high efficiency, step economy, and low catalyst loading.
Synthesis of Isoquinolines through Ir<sup>III</sup>
-Catalyzed C-H Activation/Annulation from Benzimidates with Hydroxylisopropylalkynes
作者:Mingliang Liu、Wanchun Gong、Erli You、Haizhen Zhang、Lei Shi、Weiguo Cao、Jingjing Shi
DOI:10.1002/ejoc.201800410
日期:2018.9.30
An IrIII‐catalyzed cascade reaction consisting of C–H activation and annulation of benzimidates with hydroxylisopropylalkynes yields a broad range of isoquinolines in one step with good functional‐group tolerance and high efficiency.
Anthranil: An Aminating Reagent Leading to Bifunctionality for Both C(sp<sup>3</sup>)−H and C(sp<sup>2</sup>)−H under Rhodium(III) Catalysis
作者:Songjie Yu、Guodong Tang、Yingzi Li、Xukai Zhou、Yu Lan、Xingwei Li
DOI:10.1002/anie.201602224
日期:2016.7.18
nitrogenation suffered from simple amidation/amination with limited atom‐economy and is mostly limited to C(sp2)−H substrates. In this work, anthranil was designed as a novel bifunctional aminating reagent for both C(sp2)−H and C(sp3)−H bonds under rhodium(III) catalysis, thus affording a nucleophilic aniline tethered to an electrophilic carbonyl. A tridendate rhodium(III) complex has been isolated as the