A versatile method for carbon-nitrogen bond formation via ene reactions of acylnitroso compounds

Hetero‐Diels‐Alder‐Reaktionen von Nitrosocarbonylverbindungen als nützliches Verfahren in der organischen Synthese

“…[114] Eine ähnliche Reaktivität wurde bei der Reaktion der bicyclischen Cycloaddukte 67 mit Dialkylzinkreagentien in Gegenwart von Kupferkatalysatoren beobachtet. [115,116] Wenngleich ein Angriff an der Carbonylfunktion gemäß den Un- tersuchungen von Keck zu erwarten wäre, [85] wurden keine durch einen Angriff an der "A"-Position gebildeten Produkte beobachtet. Erneut macht dies wahrscheinlich die Schwä-chung der C-O-Bindung in einer metallkoordinierten Spezies, zum Beispiel in Komplex 93, deutlich.…”

Catalytic amination reactions mediated by Co(II) Schiff base complexes

“…Stoichiometric allylic amination of olefins has been performed with sulfur [11,12] and selenium [13] imido compounds and proceeds with retention of the double bond position. On the other hand several indirect routes mostly based on ene reactions of organonitrogen compounds, including azo- [14][15][16], nitroso- [17][18][19][20], and N-sulfinylcarbamate derivatives [21], exhibit high regioselectivities with double bond transposition, but require additional N-N or N-O reduction steps to produce allyl amines. The metal-catalyzed direct electrophilic amination of alkenes represents an attractive way for the synthesis of allylic amines.…”

Allylic Amidation of Olefins by Ene Reaction of Acylnitroso Compounds Generated in situ by Oxidation of Hydroxamic Acids

“…While the mild oxidants iodine and 2,3-dichloro-4,5-to be generated in situ because of their low persistence; a dicyanobenzoquinone (DDQ) were ineffective in oxidizing result of their high electrophilic reactivity. [6] the benzylhydroxamic acid (1b), in the case of lead tetraIn this context, Kirby et al [7] [8] and Keck et al [9] gener-acetate, tetraethylammonium periodate, [12] and the DessϪ ated acylnitroso intermediates by thermal retrocleavage of Martin reagent, complex side reactions with low yields (ca. their DielsϪAlder adducts with 9,10-dimethylanthracene or 20%) of the ene product were observed.…”

“…[9] This work reports a viable synthetic meth-stituent for the latter, i.e., p-NO 2 (1c) versus p-MeO (1e), odology (Scheme 1) and demonstrates that good yields of matters little to the efficacy of the ene reaction of the inthe intermediary acylnitroso can be achieved under mild situ generated N-acylnitroso enophile with a reactive olefin conditions, as manifested by the ene reaction with the ap-such as tetramethylethylene. In contrast, the less electronrich 2-methylbutene (3b) with the most reactive p-nitro-sub- General Procedure for the Nitroso Ene Reaction: Hydroxamic acid (1.3 mmol), dissolved in CH 2 Cl 2 /DMF (10:1, 25 mL) was added over a period of 8 h to a solution of the olefin (4.0 mmol) and iodosobenzene diacetate (1.5 mmol) in CH 2 Cl 2 (25 mL) at 0°C.…”