α-Functionalization of Nitroalkenes and Its Applications in Organic Synthesis

Abstract

The applications of Morita-Baylis-Hillman (MBH) and Rauhut-Currier (RC) adducts of nitroalkenes in the synthesis of various carbo-and heterocycles are summarized in this review. In recent years, the MBH adducts and their derivatives such as acetates and bromides have served as efficient synthons for the synthesis of bioactive compounds including natural products. The close proximity of various functional groups makes the MBH and RC adducts extremely valuable substrates in multicomponent and cascade reactions, including annulations, organocatalysis, and kinetic resolution, to name a few.

Recent advances in the synthetic applications of Morita–Baylis–Hillman and Rauhut–Currier adducts of nitroalkenes

“…9 After that, several electrophiles were used in the MBH and RC reactions of nitroalkenes 1 , including different aldehydes, imines, imines generated in situ from aldehydes and amines, azodicarboxylates, vinyl ketones, vinyl sulfones, vinyl esters, etc . 10…”

“…The synthetic applications of RC and MBH adducts of nitroalkenes until 2015 were reported in the previous reviews by our group and the Chen group. 10 In this review, we discuss the applications of RC and MBH adducts of nitroalkenes that appeared from 2015 to date.…”

Stereocontrolled Construction of Spirooxindole-Containing 5,6,7,8-Tetrahydropyrrolo[1,2-a]pyridine via Michael/Friedel–Crafts Domino Reaction Promoted by Secondary Amine-Squaramide

“…On the other hand, Morita–Baylis–Hillman (MBH) nitroallylic acetates were documented as 1,2- or 1,3-bielectrophiles in various cascade Michael/Michael processes . In this context, MBH nitroallylic acetates have gained much attention from organic chemists, and numerous elegant protocols have been developed to construct diverse cyclic compounds, especially in an enantioenriched fashion .…”

Catalyst- and Base-Free Synthesis of Morita–Baylis–Hillman and Rauhut–Currier Adducts of β-Aminonitroalkenes

“…Several alkenes and electrophiles were used in these reactions thereafter, including conjugated ketones, esters, sulfones, acrylates, etc . , In 2004, for the first time, our group reported the MBH reaction of conjugated nitroalkenes using formaldehyde as the electrophile to synthesize various α-hydroxymethylated nitroalkenes . Later, several electrophiles such as aldehydes, imines, azodicarboxylates, vinyl ketone, vinyl sulfone, vinyl esters, in situ generated imines, etc ., were used in MBH and RC reactions of nitroalkenes. , The MBH and RC adducts of nitroalkenes thus obtained have also been found to possess significant biological properties − as well as useful in the construction of various drugs and natural products . However, in many MBH and RC reactions, the use of stoichiometric amounts of nucleophilic bases such as DABCO, DMAP, quinuclidine, phosphine, etc ., was necessary for the complete conversion of the starting material(s) which was less appealing. ,, Therefore, reagent- and catalyst-free synthesis of MBH and RC adducts via modification of substrate(s) and/or reaction conditions is of keen interest from the perspective of synthetic efficiency and sustainability.…”

“…Later, several electrophiles such as aldehydes, imines, azodicarboxylates, vinyl ketone, vinyl sulfone, vinyl esters, in situ generated imines, etc ., were used in MBH and RC reactions of nitroalkenes. , The MBH and RC adducts of nitroalkenes thus obtained have also been found to possess significant biological properties − as well as useful in the construction of various drugs and natural products . However, in many MBH and RC reactions, the use of stoichiometric amounts of nucleophilic bases such as DABCO, DMAP, quinuclidine, phosphine, etc ., was necessary for the complete conversion of the starting material(s) which was less appealing. ,, Therefore, reagent- and catalyst-free synthesis of MBH and RC adducts via modification of substrate(s) and/or reaction conditions is of keen interest from the perspective of synthetic efficiency and sustainability. Incidentally, Nemes et al reported the reaction of 2-nitromethylene-pyrrolidine with di- and tricarbonyl compounds and a one-pot reaction with glyoxylate and aniline with limited substrate scope .…”