Journal ArticleDOI
Cesium effect: high chemoselectivity in direct N-alkylation of amines
TLDR
The results demonstrated this methodology was highly chemoselective to favor mono-N-alkylation over dialkylation, offering wide applications in peptidomimetic syntheses.Abstract:
A novel method for the mono-N-alkylation of primary amines, diamines, and polyamines was developed using cesium bases in order to prepare secondary amines efficiently. A cesium base not only promoted alkylation of primary amines but also suppressed overalkylations of the produced secondary amines. Various amines, alkyl bromides, and alkyl sulfonates were examined, and the results demonstrated this methodology was highly chemoselective to favor mono-N-alkylation over dialkylation. In particular, use of either sterically demanding substrates or amino acid derivatives afforded the secondary amines exclusively, offering wide applications in peptidomimetic syntheses.read more
Citations
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Journal ArticleDOI
Photocatalytic Generation of Aminium Radical Cations for C─N Bond Formation.
TL;DR: This Perspective covers recent synthetic methods that rely on the photocatalytic generation of aminium radical cations for C─N bond formation, specifically in the context of alkene hydroamination, arene C─H bond amination, and the mesolytic bond cleavage of alkoxyamines.
Journal ArticleDOI
Synthesis of N,N,N-trimethyl chitosan homopolymer and highly substituted N-alkyl-N,N-dimethyl chitosan derivatives with the aid of di-tert-butyldimethylsilyl chitosan
Berglind Eva Benediktsdóttir,Vivek S. Gaware,Ögmundur Vidar Rúnarsson,Ögmundur Vidar Rúnarsson,Sigríður Jónsdóttir,Knud J. Jensen,Már Másson +6 more
TL;DR: In this paper, a highly chemoselective strategy for the synthesis of N,N,N-trimethyl chitosan (TMC) homopolymer and highly substituted N-alkyl-N, N-dimethyl (N-Dimethyl) chitosaan derivatives was achieved using di-tert-butyldimethylsilyl-3,6-O-chitosans (di-TBDMS chitoan) as a precursor.
Journal ArticleDOI
Aqueous-Mediated N-Alkylation of Amines
TL;DR: In this article, direct N-alkylation of primary amines to secondary/tertiary amines and of secondary amines in the presence of NaHCO3 in an aqueous medium at an elevated temperature is described.
Journal ArticleDOI
Anti-Markovnikov Hydroamination of Unactivated Alkenes with Primary Alkyl Amines.
David C. Miller,Jacob M. Ganley,Andrew J. Musacchio,Trevor C. Sherwood,William R. Ewing,Robert R. Knowles +5 more
TL;DR: High selectivities are observed for secondary over tertiary amine products, even though the secondary amines are estab-lished substrates for ARC-based olefin amination under similar conditions.
Journal ArticleDOI
Synthesis of 2-substituted quinazolines by CsOH-mediated direct aerobic oxidative cyclocondensation of 2-aminoarylmethanols with nitriles in air
Song Yao,Song Yao,Kaijing Zhou,Jiabing Wang,Hongen Cao,Lei Yu,Jianzhang Wu,Peihong Qiu,Xu Qing,Xu Qing,Xu Qing +10 more
TL;DR: In this article, a highly atom-efficient synthesis of 2-substituted quinazolines is developed by a CsOH-mediated direct aerobic oxidative reaction of the readily available and stable 2-aminoarylmethanols and nitriles.
References
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Book
Reagents for Organic Synthesis
TL;DR: In this paper, the authors propose a method for using Reference Abbreviations (RABs) as a reference abbreviation for reference abbreviations in the context of bioinformatics.
Journal ArticleDOI
Synthesis of secondary amines
Journal ArticleDOI
An assessment of the causes of the cesium effect
TL;DR: In this paper, the effect of this effect on macrocyclization by means of nucleophilic substitution is discussed. But it is concluded that the cesium ion is virtually completely solvated and that carboxylates are essentially free and highly reactive.