Catalytic Regio- and Enantioselective Oxytrifluoromethylthiolation of Aliphatic Internal Alkenes by Neighboring Group Assistance
作者:Jia Xu、Yuanyuan Zhang、Tian Qin、Xiaodan Zhao
DOI:10.1021/acs.orglett.8b02672
日期:2018.10.19
Chiral selenide-catalyzed oxytrifluoromethylthiolation of aliphatic internal alkenes by a formally intermolecular strategy is disclosed, affording CF3S 1,3-amino alcohol and 1,3-diol derivatives with high regio-, enantio-, and diastereoselectivities. The reactions are promoted by a neighboring imide or ester group on substrates via a six-membered ring transition state. This assistance strategy is also
公开了通过形式上的分子间策略手性硒化物催化的脂肪族内烯烃的氧三氟甲基硫醇化,提供了具有高区域,对映体和非对映选择性的CF 3 S 1,3-氨基醇和1,3-二醇衍生物。底物上相邻的酰亚胺或酯基团通过六元环过渡态促进了反应。该辅助策略也成功地应用于内部烯烃的区域和非对映选择性的氧卤官能化以及炔烃的转化。
N-Alkenyl and cycloalkyl carbamates as dual acting histamine H3 and H4 receptor ligands
Previous studies have shown that several imidazole derivatives posses affinity to histamine H-3 and H-4 receptors. Continuing our study on structural requirements responsible for affinity and selectivity for H-3/H-4 receptor subtypes, two series of 3-(1H-imidazol-4-yl) propyl carbamates were prepared: a series of unsaturated alkyl derivatives (1-9) and a series possessing a cycloalkyl group different distances to the carbamate moiety (10-13). The compounds were tested for their affinities at the human histamine H3 receptor, stably expressed in CHO-K1 cells. Compounds 1, 2, 5-7, 10-13 were investigated for their affinities at the human histamine H-4 receptor co-expressed with G alpha(i2) and G beta(1)gamma(2) subunits in Sf9 cells. To expand the pharmacological profile, compounds were further tested for their H3 receptor antagonist activity on guinea pig ileum and in vivo after oral administration to mice. All tested compounds exhibited good affinity for the human histamine H-3 receptor with K-i values in the range from 14 to 194 nM. All compounds were active in vivo after peroral administration (p.o.) to Swiss mice, thus demonstrating their ability to cross the blood-brain barrier. The most potent H-3 receptor ligand of these series was compound 5, 3-(1H-imidazol-4-yl) propyl pent-4-enylcarbamate with the highest affinity (K-i = 14 nM). Additionally, compound 3 showed remarkable central nervous system (CNS) H3R activity, increasing the N-tau-methylhistamine levels in mice with an ED50 value of 0.55 mg/kg, p.o. evidencing therefore, a twofold increase of inverse agonist/antagonist potency compared to the reference inverse agonist/antagonist thioperamide. In this study, the imidazole propyloxy carbamate moiety was kept constant. The different lipophilic moieties connected to the carbamate functionality in the eastern part of the molecule had a range of influences on the human H-4 receptor affinity (154-1326 nM). (C) 2011 Elsevier Ltd. All rights reserved.
Wiecek, Malgorzata; Kiec-Kononowicz, Katarzyna, Acta poloniae pharmaceutica, 2009, vol. 66, # 3, p. 249 - 257