The application of microwave irradiation to the Michael synthesis of esters of β-amino acids

Nonthermal Effects of Microwaves in Organic Synthesis

“…A comparative study of this procedure showed that use of microwave irradiation reduced the reaction time from several hours, if conventional heating was used, to a few minutes only (Eq. It was shown that microwave irradiation accelerated the 1,4 Michael addition of primary and cyclic secondary amines to acrylic esters, leading to several b-amino acid derivatives in good yields within short reaction times [78] (Eq. It was shown that microwave irradiation accelerated the 1,4 Michael addition of primary and cyclic secondary amines to acrylic esters, leading to several b-amino acid derivatives in good yields within short reaction times [78] (Eq.…”

An assessment of the technique of simultaneous cooling in conjunction with microwave heating for organic synthesis

“…It has also been shown that microwave heating accelerates the Michael addition of primary and cyclic secondary amines to acrylic esters. 20 The use of microwave heating for intramolecular Michael additions has been reported. A range of ortho-aminochalcones have been cyclised to tetrahydroquinolines using a clay support.…”

Microwave-initiated hydroamination of 2-ethoxypropenal with secondary amines

“…Selective conjugate addition (66%, 1 H NMR) was also observed in the reaction of 2-ethoxyprop-2-enal with piperidine and water at a ratio of 1 : 1.5 : 1.5. These findings indicate that the presence of an ethoxy group in the α-position of Michael acceptor does not prevent Michael reaction under the given conditions and provide additional information on the effect of substituents in α,β-unsaturated carbonyl compounds [10].…”

“…With a view to elucidate the effects of microwave irradiation (MW) and aqueous medium in the present work we continued our studies on the addition of secondary amines to α-ethoxyacrolein [7]. It should be noted that numerous addition reactions of secondary amines to activated α,β-unsaturated carbonyl compounds were performed with α,β-unsaturated esters, acids, amides, nitriles, and ketones [10,[12][13][14], whereas conjugated aldehydes were seldom used as Michael acceptors [13,15]. Reactions with the latter are strongly complicated by side processes, in particular by 1,2-addition with subsequent condensation, as well as by polymerization [13,16].…”

“…Michael reaction is one of the most extensively studied reactions in organic synthesis, and its potential can be increased with the use of microwave irradiation [9,10]. Furthermore, studies on Michael addition in aqueous solution have been initiated since 1990s [11].…”