New methods for the preparations of 2-aryl aziridines, α-imido styrenes, and allyl amines from olefins via diphenylvinylsulfonium triflates

Abstract

Reactions of diphenylvinylsulfonium triflates with primary amines and imides afforded 2-arylaziridines and α-imidostyrenes, respectively. These products were also obtained from styrenes in one vessel without isolation of the intermediate sulfonium salts. In addition, 1,1-disubstituted and trisubstituted alkenes were converted into allylamines via isomerization of initially formed vinylsulfonium salts to allylsulfonium salts in the presence of primary or secondary amines.

Cationic Gold Catalyzes ω-Bromination of Terminal Alkynes and Subsequent Hydroaddition Reactions

“…For N -succinimide 2b , an alternative gold-catalyzed hydroimidation of the alkyne might take place through π-attack of the amine, protodeauration, and 1,2-elimination of 2b . Anyway, this second proposal features some inconsistencies: (a) to date, no gold-catalyzed intermolecular hydroimidations of alkynes have been reported , and (b) α-imidosubstituted styrenes (those intermediates formed with 2a and 2b -type , imides) are stable compounds.…”

Synthesis of α-Substituted Vinylsulfonium Salts and Their Application as Annulation Reagents in the Formation of Epoxide- and Cyclopropane-Fused Heterocycles

“…Vinylsulfonium triflate 1 and its immediate precursor bromoethylsulfonium triflate 2 have been shown to be excellent annulation reagents in the synthesis of a wide variety of heterocyclic motifs (Scheme ). − The development of this methodology has also proven a valuable tool for the preparation of novel bioactive compounds often encountered during the drug discovery process on scales ranging from >100 mg to <1 kg. − We have been interested in expanding the scope of this methodology to include more substituted vinylsulfonium salts. Previous work reported in the literature documents several examples of the annulation properties of β-substituted vinylsulfonium salts 3 and 4 ; ,− however, to our knowledge, only two types of vinylsulfonium salt bearing α-substituents have been prepared ( 5 and 6 ) and only their use in the cyclopropanation of malonate derivatives and the aziridination of primary amines was explored (Scheme ). − While sulfonium salts of type 6 can be prepared from commercially available styrenes according to the method first reported by Chow , and then extended by Chandrasekaran, the scope of this transformation is still severely limited in terms of functional group tolerance.…”

Anti-Markovnikov rearrangement in sulfur mediated allylic C–H amination of olefins

“…A similar reaction sequence has previously been accomplished in Mukaiyama group's study using a-methylstyrene as an olefin substrate. 18,19 However, when terminal olefin 1a was examined under these conditions, the originally expected products 3aa to 3ag turned out to be the minor products, while the major products were 4aa to 4ag. If primary amine nucleophiles (2d to 2g) were used instead of secondary amine nucleophiles (2a to 2c), azetidine products 5ad to 5ag were also generated in up to 35% isolated yield.…”

“…The experiment that initiated this study was very straightforward: electrophilic addition of allylbenzene (1a) with the sulfur reagent generated from diphenylsulfoxide and triflic anhydride [15][16][17][18][19] followed by nucleophilic substitution with various amine nucleophiles (2) should give allylic C-H amination product 3 with concomitant double bond migration (Table 1). A similar reaction sequence has previously been accomplished in Mukaiyama group's study using a-methylstyrene as an olefin substrate.…”