Reactions of α-carbanions of lithium acylates with N,N-diethyl-N-chloro- and N,N-diethyl-N-bromoamines
摘要:
The interaction of alpha-carbanions of lithium acylates (prepared via metalation of acetic, butyric, or isobutyric acid with lithium diisopropylamide in tetrahydrofuran under argon atmosphere) with N,N-diethyl-N-chloro- or N,N-diethyl-N-bromoamine has resulted in the formation of succinic acid or its 2,3-diethyl- and 2,2,3,3-tetramethyl-substituted derivatives in yields of 47-66% and the corresponding alpha-halocarboxylic acids (12-34%). Anion-radical scheme of the reaction products formation has been suggested.
The Synthesis of 11-(2′-Dimethylaminoethyl)-5-methyl-5,11-dihydrodibenzo[<i>b</i>,<i>e</i>][1,4]thiazepin and Related Compounds. Neurotropic and Psychotropic Agents
作者:Ikuo Ueda、Suminori Umio
DOI:10.1246/bcsj.48.2323
日期:1975.8
The synthesis of 11-(2′-dimethylaminoethyl)-5-methyl-5,11-dihydrodibenzo[b,e][1,4]thiazepin and related compounds is described. 11-Lithiolated 5-methyl-5,11-dihydrodibenzo[b,e][1,4]thiazepin (18) was employed as the key intermediate in the preparation of these compounds.
umpolung of cationic bromine from N-bromosuccinimide (NBS) using an amine organocatalyst is reported. The intermediate reagents and their reactivity have well been characterised by spectroscopic and computational methods. Strategic structural change in the NBS molecule can cause sufficient polarity reversal to accelerate the dibromination reaction needing both “Br” synthons. This has further been utilised
alkylaminyl radical formation and maintain the nucleophilicity of fluoride ion. This protocol exhibits excellent functional-group tolerance toward various aryl and unactivated alkenes, furnishing the corresponding β-fluoroamines with high regioselectivity. Mechanistic investigation reveals an aziridinium intermediate via a radical pathway. The syntheticutility of this transformation was demonstrated by