Dibenzoxazepinium Ylides: Facile Access and 1,3-Dipolar Cycloaddition Reactions

Abstract

An effective approach to azirino-fused heterocycles is disclosed. The approach, involving formation of heterocycle/C-(arylchloromethyl)-subsituted CN double bond via domino isomerization of a gem-dichloroaziridine-intramolecular Friedel-Crafts acylation of the O-tethered benzene ring and subsequent intramolecular cyclization induced by hydride, was realized for 1-aryl-1,11b-dihydroazirino[1,2-d]dibenz[b,f][1,4]oxazepines. The latter are excellent precursors of azomethine ylides, especially in solvent-free conditions, which can undergo a completely stereoselective 1,3-dipolar cycloaddition to CC dipolarophiles giving derivatives of dibenzo[b,f]pyrrolo[1,2-d][1,4]oxazepine.

Fused aziridines as sources of azomethine ylides

“…A recently proposed simple method for the synthesis of azirinodibenzazepines and oxazepines 26a,b made it possible to use these compounds as sources of azomethine ylides 27a,b and to obtain a wide range of potential biologically active pyrrolodibenzazepines and oxazepines 28a,b and 29a,b [15,16]. Dipolarophiles RHC=CHR…”

Catalytic Asymmetric Reactions Involving the Seven‐Membered Cyclic Imine Moieties Present in Dibenzo[b,f][1,4]oxazepines

“…In this context, 11‐substituted 10,11‐dihydrodibenzo[ b , f ][1,4]oxazepine derivatives play an important role in medicinal chemistry, Compound 2 (Figure ), for example, shows antidepressant activity, and compound 3 is a progesterone receptor agonist, whereas compound 4 presents antihistaminic activity . Despite the importance of this pharmacophore, catalytic asymmetric methodologies for the preparation of enantioenriched 11‐substituted 10,11‐dihydrodibenzo[ b , f ][1,4]oxazepine derivatives are scarce in the literature . This review covers the achievements in the catalytic enantioselective synthesis of such compounds, paying attention to the reactions used and also to the transformations carried out on the resulting chiral dihydrodibenzo[ b , f ][1,4]oxazepine derivatives.…”

PEG400-enhanced synthesis of gem-dichloroaziridines and gem-dichlorocyclopropanes via in situ generated dichlorocarbene

“…gem-Dichloroaziridines have broad application as significant intermediates in pharmacological and organic synthesis. [1][2][3][4] Most importantly, gem-dihalocyclopropanes are valuable substrates in the preparation of cyclopropane and allene derivatives, which are fine chemicals with functional groups for further derivatization. 5,6 There are three main routes to the gem-dichloroaziridine when utilizing dichlorocarbene as the starting material, 7 i.e.…”