Selective N-dealkylation of tertiary amines derived from phenylglycinol or ephedrine family
摘要:
Tertiary amines bearing an hydroxyethyl group derived from phenylglycinol, norephedrine or norpseudoephedrine can be selectively dealkylated using a two-step sequence involving treatment with thionyl chloride in THF, followed by reaction with an excess of potassium cyanide in THF:DMSO. These conditions are compatible with the presence of an insaturation or a benzyl ether in the substrate. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.
N,N-Dialkyl-β-amino alcohols were enantiospecifically and regioselectively rearranged by using N,N-diethylaminosulfur trifluoride (DAST) to give optically active β-fluoroamines in excellent yields and enantiomeric excesses. This rearrangement was applied to the enantioselectivesynthesis of LY503430, a potential therapeutic agent for Parkinson’s disease.
Preparation of Aminoalkyl Chlorohydrin Hydrochlorides: Key Building Blocks for Hydroxyethylamine-Based HIV Protease Inhibitors
作者:Pierre L. Beaulieu、Dominik Wernic
DOI:10.1021/jo960109i
日期:1996.1.1
N-dibenzyl-alpha-amino aldehydes reacted with (chloromethyl)lithium, generated in situ from bromochloromethane and lithium metal, to give predominantly erythro aminoalkyl epoxides. Treatment of the crude epoxides with aqueous hydrochloric acid gave crystalline (2S,3S)-N,N-dibenzylamino chlorohydrin hydrochlorides in 32-56% overall yield and high isomeric purity. These compounds are versatile synthetic intermediates
Aldol Reactions between L-Erythrulose Derivatives and Chiral α-Amino and α-Fluoro Aldehydes: Competition between Felkin-Anh and Cornforth Transition States
作者:Santiago Díaz-Oltra、Miguel Carda、Juan Murga、Eva Falomir、J. Alberto Marco
DOI:10.1002/chem.200800956
日期:2008.10.20
Both matched and mismatched diastereoselection have been observed in aldolreactions of a boronenolate of a protected L-erythrulose derivative with several chiral alpha-fluoro and alpha-amino aldehydes. Strict adherence to the Felkin-Anh model for the respective transitionstructures does not account satisfactorily for all the observed results, as previously observed in the case of alpha-oxygenated
the synthesis of α‐fluoro‐β‐aminophosphonates by the regioselectivefluorination of α‐hydroxy‐β‐aminophosphonates under mild conditions. The fluorination reactions were mediated by the PyFluor reagent and occurred with the retention of configuration. The main products of this reaction were a series of α‐fluoro‐β‐aminophosphonates, which can be used as precursors in the preparation of medicinally important
Copper-Catalyzed Regio- and Enantioselective Aminoboration of Unactivated Terminal Alkenes
作者:Kodai Kato、Koji Hirano、Masahiro Miura
DOI:10.1002/chem.201801070
日期:2018.4.17
A CuCl/(R,R)‐PTBP‐BDPP‐catalyzedregioselective and enantioselective aminoboration of simple and unactivatedterminalalkenes with bis(pinacolato)diboron (pinB‐Bpin) and hydroxylamines has been developed. The amino group and boryl group were incorporated at the internal position and terminal position, respectively, and the corresponding chiral β‐borylalkylamines were obtained with good to high enantiomeric