A 3-azacyclopropanespiro-1,2-dioxetane via singlet oxygenation of a methyleneaziridine

Observations on the ring opening reactions of 2-methyleneaziridines with acid chlorides and alkyl chloroformates

“…These were made in two simple steps by N-alkylation of the appropriate primary amine with 2,3-dibromopropene in the presence of potassium carbonate and subsequent ring closure using excess sodium amide in liquid ammonia (Table 1). 1,2 Pure methyleneaziridines were obtained in modest but acceptable yields after chromatography on basic alumina (8) or bulb to bulb distillation (7,9,10). The successful synthesis of 1-benzyl-2-methyleneaziridine 7 by this method is notable as we had previously incorrectly reported that it cannot be made using the Pollard and Parcell cyclisation protocol.…”

Methyleneaziridines: Unusual Vehicles for Organic Synthesis

“…This yield is comparable to that obtained in solution (Scheme 11). 27 The optimised conditions differ from the solution-phase reaction in several (59) respects. Not unexpectedly, higher quantities of the reagents (RMgCl, CuI and electrophile) were required to effect good conversions.…”

“…These heterocycles react with tetracyanoethylene to produce 1,1,2,2-tetracyano-5-azaspiro [3.2] 59 Methyleneaziridines also react with alkyl 48 and sulfonyl azides 17 to give triazoles and 2-(sulfonylimino)azetidines, respectively. These observations have been rationalised in terms of initial [3+2] cycloaddition between the azide moieties and the exocyclic double bond, followed by subsequent rearrangements of the resulting spirotriazolines.…”

“…57,58 Akasaka et al have shown that reaction of 2-adamantylidene-N-tert-butylaziridine with singlet oxygen produces the corresponding 1,2-dioxetane as an unstable intermediate by a related [2p+2p] cycloaddition. 59 Methyleneaziridines also react with alkyl 48 and sulfonyl azides 17 to give triazoles and 2-(sulfonylimino)azetidines, respectively. These observations have been rationalised in terms of initial [3+2] cycloaddition between the azide moieties and the exocyclic double bond, followed by subsequent rearrangements of the resulting spirotriazolines.…”

Aziridinyl anions from a chiral, nonracemic 2-isopropylidineaziridine: surprisingly diastereoselective alkylation reactions

“…As 2-alkylidineaziridines participate in a variety of useful transformations including radical rearrangements, 8 multicomponent reactions, 7,9 and oxidative cleavage processes to alactams, 10 it is anticipated that the methodology described herein will find a number of useful applications in asymmetric synthesis. The use of a chiral, nonracemic element on nitrogen to control the diastereoselectivity of the alkylation of unsubstituted aziridinyl anions (Scheme 1, X = H) is novel.…”