Aqueous‐Mediated N‐Alkylation of Amines

Abstract

Direct N‐alkylation of primary amines to secondary/tertiary amines and of secondary amines to tertiary amines has been achieved in excellent yields by employing alkyl, benzylic and allylic halides in the presence of NaHCO3 in an aqueous medium at an elevated temperature. Amines of differentstereoelectronic nature react with ease with different halides. The selective formation of secondary amines and the formation of three different substituted tertiary amines are some of the interesting features of this methodology. Reaction in an aqueous medium, operationally convenient conditions, excellent yields and innocuous byproducts, and the absence of transition‐metal catalysts, expensive bases, solid supports and the formation of undesired quaternary ammonium salts makes this method a green chemical process. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Insight into luminescence enhancement of coordinated water-containing lanthanide metal–organic frameworks by guest molecules

“…8 Synthesis of [Tb(HL)(H 2 O) 2 ]·2(DMA)·0.5(H 2 O) (1a) H 4 L (0.09 g, 0.2 mmol) was dissolved in a mixture of DMA (4.5 mL) and H 2 O (0.5 mL). Then Tb(NO 3 ) 3 ·6H 2 O [0.2 mL, 0.2 mmol, (1.0 M in water)] was added.…”

N-Alkylations of chitosan promoted with sodium hydrogen carbonate under aqueous conditions

“…N-Alkylations of chitosan were carried out by a modified method reported by Singh et al [10], as follows. For example, chitosan (1.06 g; 5 mmol of C2-amine groups) and a designed amount of either monobromoacetic acid or monochloroacetic acid were dissolved in deionized water (50 mL).…”

“…Monochloroacetic acid and 3-chloropropionic acid have been used so far in the N-alkylations of chitosan under aqueous conditions, and these N-alkylations proceed by S N 2 (nucleophilic substitution, 2nd order) reactions, while the reaction with benzyl bromide proceeds by S N 1 reaction. It was reported by Singh et al that benzyl bromide could react with low-molecular-weight amines to form N,N-dibenzyl amines by the N-alkylation under aqueous conditions [10]. However, this N-benzylation has not been applied to chitosan yet.…”

Ruthenium‐Catalyzed Synthesis of Secondary Alkylamines: Selective Alkylation with Aliphatic Amines

“…Due to their numerous applications in polymers, dyes, agrochemicals, and pharmaceuticals, [1] there is an ongoing interest for improved and new synthetic preparations. [2] Besides the well known N-alkylations of amines with alkyl halides, [2,3] catalytic methodologies such as reductive amination, [2,4] hydroaminations, [5] and hydroaminomethylations [6] of olefins or alkynes have been developed for the synthesis of aliphatic amines within the last decade. In addition, the environmentally friendly Nalkylation of amines using primary [7] and secondary alcohols [8,9] has attracted considerable interest.…”