N-Dienyl lactams: preparation and selectivity in the Diels-Alder reaction

Abstract

We have shown that N-dienyl lactams are prepared in good yield by reaction of a lactam with an a,@-unsaturated aldehyde. The N-dienyl lactam is obtained with good selectivity for theEJ-isomer. The N-dienyl lactams are excellent enophiles and react with electron-deficient olefins to give exclusively the ortho regioisomer with good selectivity for the endo (2) adduct, similar to results observed for dienyl amides. In addition, the yield of the Diels-Alder adduct can be significantly enhanced by the use of aqueous solvents when compared to traditional aprotic solvents.

Organic Reactions in Aqueous Media with a Focus on Carbon−Carbon Bond Formations: A Decade Update

“…822 The reaction of dienes bearing an N-dienyl lactam moiety with activated olefins was examined by Smith. 823 The lactams were excellent enophiles and provided exclusively the ortho regioisomer with good selectivity for the endo (Z) product (eq 204).…”

Multicomponent Coupling Reactions for Organic Synthesis: Chemoselective Reactions with Amide–Aldehyde Mixtures

“…Although several syntheses of 1-N-acylaminodienes have been reported by Oppolzer, [23] Overman, [24] and others, [25] our one-pot procedure is unique in that it merely involves mixing of ubiquitous available amides and aldehydes at elevated temperature. [26] The inherent selective telomerization of two aldehydes with one amide molecule is especially remarkable when considering the numerous side reactions which are likely to proceed under the acidic reaction conditions (further aldol condensations, oligomerizations etc.).…”

β-Aminophosphonic compounds derived from methyl 1-dimethoxyphosphoryl-2-succinimidocyclohex-3-ene-1-carboxylates

“…N-Buta-1,3-dienylsuccinimide 1 9 (stable under our experimental conditions), cycloadds to vinylphosphonate dienophiles, provided that they are activated by an electronwithdrawing substituent in the geminal 7 or vicinal position. 8 This is exemplified by the reaction with trimethyl 2-phosphonoacrylate 2 10 furnishing a 65 : 35 mixture of stereoisomers 3a and 3b in 93% yield (Scheme 1).…”