82259-99-2Relevant academic research and scientific papers
Synthesis of &γ-Aminobutyric Acid Analogue of Restricted Conformation. Part 1. The 2-(Aminomethyl)cycloalkaneacetic Acids
Kennewell, Peter D.,Matharu, Saroop S.,Taylor, John B.,Westwood, Robert,Sammes, Peter G.
, p. 2563 - 2570 (1982)
The synthesis of analogues with restricted rotatin about the C(2)-C(3) bond of γ-aminobutyric acid, namely cis- and trans-2-(aminomethyl)-cyclopropane and -cyclobutanecarboxylic acids and trans-2-(aminomethyl)cyclohexanecarboxylic acid are described.
An Efficient Route to GABA-Analogous Amino Acids: Cyclopropanation of N-Silylated Allylamines and Enamines
Paulini, Klaus,Reissig, Hans-Ulrich
, p. 455 - 461 (2007/10/02)
N-Silylated allylamines 1 are effectively transformed into methyl cyclopropanecarboxylates 2 by methyl diazoacetate under Rh2(OAc)4 catalysis.Derivatives 2a and 2b are smoothly converted into trans-substituted amino acids 6a and 6b, respectively, and to bicyclic γ-lactams 5a and 5b.The pharmacologically interesting γ-aminobutyric acid (GABA) analogue trans-6a is now available in few steps.Photochemical and thermal Fe(CO)5-induced hydrogen shift converts allylamine derivatives 1 into N-silylated enamines 7.While enamine (E)-7a can be cyclopropanated with methyl diazoacetate under Cu(acac)2 catalysis to afford the desired cyclopropane derivatives 8a in good yield, the other enamines are rather unreactive towards the carbenoid.Use of an optically active catalyst provides 8a with an ee of 56percent (cis) and 20percent (trans).Acid induced ring cleavage of 8a gives the β-formyl ester 10a, and reduction of 8a followed by desilylation provides the aminocyclopropane 14 in good overall yield, thus demonstrating that cyclopropanes like 8a can serve as useful synthetic intermediates. --- Key Words: Amino acids / GABA analogues / Aminocyclopropanes / Enamines, N-silylated / Cycloaddition
