The hetero Diels-Alder reaction is one of the most important methods for the synthesis of heterocycles. In this article an overview is given for the period since 1989 describing the reaction of heterobutadienes such as oxabutadienes, thiabutadienes, azabutadienes, diaazabutadienes, nitroso-alkenes and nitroalkenes as well as of heterodienophiles such as carbonyls, thiocarbonyls, imines, iminium salts, azo- and nitroso compounds. In addition, several other less common hetero Diels-Alder reactions such as cycloadditions of thiaazabutadienes, oxaazabutadienes, dioxabutadienes, dithiabutadienes, oxathiabutadienes, diazaoxabutadienes as well as the use of N-sulfinyl-phosphaalkynes and other dienophiles are mentioned. A main point of discussion is the stereoselectivity of the reactions and the preparation of enantiopure compounds either using dienes and dienophiles carrying a chiral auxiliary or employing chiral Lewis acids. A point stressed is the synthesis of natural products using hetero Diels-Alder reactions leading to carbohydrates, alkaloids, terpenes, antibiotics, mycotoxins, cytochalasans, antitumor agents and several other classes of natural products.

Hetero diels-alder reactions in organic chemistry

Orbital Symmetries and endo-exo Relationships in Concerted Cycloaddition Reaction (福井謙一とフロンティア軌導理論) -- (参考論文)

Organic transformations that result in the formation of multiple covalent bonds within the same reaction are some of the most powerful tools in synthetic organic chemistry. Nitrosocarbonyl hetero-Diels–Alder (HDA) reactions allow for the simultaneous stereospecific introduction of carbon–nitrogen and carbon–oxygen bonds in one synthetic step, and provide direct access to 3,6-dihydro-1,2-oxazines. This Review describes the development of the nitrosocarbonyl HDA reaction and the utility of the resulting oxazine ring in the synthesis of a variety of important, biologically active molecules.

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The Nitrosocarbonyl Hetero-Diels–Alder Reaction as a Useful Tool for Organic Syntheses

Recent development in preparation reactivity and biological activity of enaminoketones and enaminothiones and their utilization to prepare heterocyclic compounds

Medium ring lactones

[4+2] cycloaddition reactions of various 1,3-diaza-1.3-Butadienes with ketenes

Diels-Alder cycloaddition reactions of 1,3-diazabutadienes with sulfene

Reactions of 1,3-diaza-1,3-butadienes with haloketenes - rearrangements accompanying [4+2] cycloaddition reactions.

Synthesis of 5-isopropenyl/vinyl substituted pyrimidinone via 4+2 cycloaddition reactions of 1,3-diaza-1,3-butadienes with isopropenyl/vinylketenes an d their further transformations: 4+2 and unusual 3+2 cycloadditions with al pha -nitrosostyrenes

Mohinder P. Mahajan

Papers

[4+2] cycloaddition reactions of various 1,3-diaza-1.3-Butadienes with ketenes

Diels-Alder cycloaddition reactions of 1,3-diazabutadienes with sulfene

Reactions of 1,3-diaza-1,3-butadienes with haloketenes - rearrangements accompanying [4+2] cycloaddition reactions.

Synthesis of 5-isopropenyl/vinyl substituted pyrimidinone via 4+2 cycloaddition reactions of 1,3-diaza-1,3-butadienes with isopropenyl/vinylketenes an d their further transformations: 4+2 and unusual 3+2 cycloadditions with al pha -nitrosostyrenes

Diels-Alder cycloaddittion reactions of enaminothions with nitroalkenes