Anionic Reactions of N‐(trans‐2,3‐Diphenylaziridin‐1‐yl)imines and Their Use as 1,1‐Dipoles in Anionic Cyclizations

Abstract

Reaction of N-(trans-2,3-diphenylaziridin-1-yl)imines with alkyllithiums and organocuprates afforded the desired addition products after consecutive fragmentations along with liberation of stilbene and nitrogen gas, while the reaction of N-(2-phenylaziridin-1-yl)imines under similar conditions gave an anomalous by-product. Anionic cyclizations of N-(trans-2,3-diphenylaziridin-1-yl)imines using unactivated alkenes and alkynes as acceptors proceeded smoothly, yielding cyclized products in good yields.

N,N-Dialkylhydrazones in Organic Synthesis. From Simple N,N-Dimethylhydrazones to Supported Chiral Auxiliaries

“…The reaction of N -( trans -2,3-diphenylaziridin-1-yl)imines 509 with alkyllithiums R 2 Li (Scheme ) afforded the products 510 (59−70% yield) via anionic addition followed by fragmentation with the liberation of stilbene and nitrogen gas. The reaction was also effective for the aziridines 509 where R 1 = PhO(CH 2 ) 4 using organocuprates where R 2 = n -Bu (68%), Grignard reagent R 2 = n -Bu, allyl (59%, 84%), and organolithiums n -BuLi (52%) and PhCC-Li (75%) . The analogous reaction of monosubstituted Eschenmoser hydrazones, N -(2-phenylaziridin-1-yl)imines, gave an anomalous byproduct.…”

“…The reaction was also effective for the aziridines 509 where R 1 ) PhO(CH 2 ) 4 using organocuprates where R 2 ) n-Bu (68%), Grignard reagent R 2 ) n-Bu, allyl (59%, 84%), and organolithiums n-BuLi (52%) and PhCC-Li (75%). 323 The analogous reaction of monosubstituted Eschenmoser hydrazones, N-(2-phenylaziridin-1-yl)imines, gave an anomalous byproduct. The consecutive trapping reactions of the putative anionic intermediates with benzaldehyde and anhydrides were probed with varying degrees of success.…”

“…On the other hand, anionic cyclizations of N-(trans-2,3-diphenylaziridin-1-yl)imines using unactivated alkenes and alkynes as acceptors proceeded smoothly, yielding various cyclized products 513 in good yields (60-91%, Scheme 96) and preference for the trans-isomers (X ) Me or -CHdCH 2 ). 323…”

“…The consecutive trapping reactions of the putative anionic intermediates with benzaldehyde and anhydrides were probed with varying degrees of success. On the other hand, anionic cyclizations of N -( trans -2,3-diphenylaziridin-1-yl)imines using unactivated alkenes and alkynes as acceptors proceeded smoothly, yielding various cyclized products 513 in good yields (60−91%, Scheme ) and preference for the trans -isomers (X = Me or −CHCH 2 ) …”

Ring-Closure Reactions of 1,2-Diaza-4,5-benzoheptatrienyl Metal Compounds: Experiment and Theory

“…A few years later, a great number of studies were undertaken to fill the general rules with examples, adjustments for special types of reactions or particular cases, and experimental approval or disapproval . There are still new aspects appearing that proove the high complexity of this topic …”