Side-chain modified analogues of histaprodifen: Asymmetric synthesis and histamine H1-receptor activity
摘要:
New analogues of histaprodifen with polar side chains have been stereo selectively synthesized and evaluated as histamine H-1-receptor agonists. As a key transformation the asymmetric aminohydroxylation has been used, which was successfully realized for the first time on an imidazolyl derivative. While all chiral analogues proved to be weak H-1-receptor antagonists, an achiral keto derivative of histaprodifen turned out to be the first 2-acylated histamine congener displaying partial H-1-receptor agonism (relative potency 12%). (c) 2005 Elsevier Ltd. All rights reserved.
Stereocontrolled Total Synthesis of (−)-Ephedradine A (Orantine)
作者:Wataru Kurosawa、Toshiyuki Kan、Tohru Fukuyama
DOI:10.1021/ja036011k
日期:2003.7.1
The stereocontrolledtotalsynthesis of (-)-ephedradine A has been accomplished. The synthesis features an asymmetric C-H insertion reaction, an intramolecular ester-amide exchange reaction, and a Sharpless asymmetric aminohydroxylation reaction. Construction of the complex macrocyclic ring was performed by Ns-strategy and an intramolecular aza-Wittig reaction.
The stereocontrolled total synthesis of (−)-ephedradine A (1) has been accomplished. Construction of opticallyactive dihydrobenzofuran-ring was performed by a novel asymmetric C–H insertion reaction. After an intramolecular ester–amide exchange reaction and a Sharpless asymmetric aminohydroxylation reaction, construction of the complex macrocyclic ring was performed by Ns-strategy and an intramolecular
Twofold Radical-Based Synthesis of <i>N</i>,<i>C</i>-Difunctionalized Bicyclo[1.1.1]pentanes
作者:Helena D. Pickford、Jeremy Nugent、Benjamin Owen、James. J. Mousseau、Russell C. Smith、Edward A. Anderson
DOI:10.1021/jacs.1c04180
日期:2021.7.7
Bicyclo[1.1.1]pentylamines (BCPAs) are of growing importance to the pharmaceutical industry as sp3-rich bioisosteres of anilines and N-tert-butyl groups. Here we report a facile synthesis of 1,3-disubstituted BCPAs using a twofold radical functionalization strategy. Sulfonamidyl radicals, generated through fragmentation of α-iodoaziridines, undergo initial addition to [1.1.1]propellane to afford iodo-BCPAs;
A new method for the aziridination of electron-deficient olefins using an N-chloro-N-sodio carbamate is described; the reaction was promoted by phase-transfer catalysis (solid–liquid) and afforded aziridines from α,β-unsaturated ketones, esters, sulfones and amides.
The iodine‐catalyzed decarboxylative amidation of β,γ‐unsaturated carboxylic acids with chloramine salts is described. This method enables the regioselective synthesis of allylic amides from various types of β,γ‐unsaturated carboxylic acids containing substituents at the α‐ and β‐positions. In the reaction, N‐iodo‐N‐chloroamides, generated by the reaction of a chloramine salt with I2, function as a