An-Hu Li

The Aziridination of N-Tosylimines with Amide-Stabilized Sulfonium Ylides: A Simple and Efficient Preparation of Aziridinyl Carboxamides

Abstract Reaction of N -sulfonylimines 2 with N,N -dialkylcarbamoylmethyl dimethylsulfonium bromides 3 in the presence of solid KOH gives the aziridinyl carboxamides 4 in good to excellent yields.

Synthesis of 2-(α-Substituted N-Tosylaminomethyl)-2,5-Dihydrofurans by Reaction of N-Sulfonylimines with Arsonium or Sulfonium 4-Hydroxyl-cis-2-butenylides

Abstract On treatment of N -tosylimines 1 and 4-hydroxyl- cis -butenyl arsonium salt 5 or sulfonium salt 11a with KOH in acetonitrile at room temperature, 2-(α-substituted N -tosylaminomethyl)-2,5-dihydrofurans 4 were obtained in moderate yields through a new ylide cyclization process. Ylide 2 acts formally as an equivalent of the 2,5-dihydrofuran anion. However, the reaction of 4-hydroxyl- trans -butenyl sulfonium salt 11b with N -tosylimine 1b under the same conditions gave only the normal aziridination product 12 . A plausible mechanism was proposed for this new 5-membered cyclization reaction, and a high yield process for the synthesis of target molecules 4 is also recommended.

Facile preparation of vinylaziridines by the reaction of N-sulfonylimines and cinnamyl bromide mediated by a catalytic amount of dimethyl sulfide

β-Phenylvinylaziridines are prepared in moderate to good yields from the reaction of N-sulfonylimines and cinnamyl bromide mediated by a catalytic amount of dimethyl sulfide in the presence of solid K2CO3 in acetonitrile at ambient temperature.

AZIRIDINATION OF N-SULFONYLIMINES WITH A STABILIZED SULFONIUM YLIDE : SIMPLE PREPARATION OF N-SULFONYL-2-(E)-2(ALKOXYCARBONYL)ETHENYL-3-ARYLAZIRIDINES

N-Sulfonyl-2-[(E)-2-(alkoxycarbonyl)ethenyl]-3-arylaziridines 1 are efficiently prepared either by the reaction of N-sulfonylimines 2 with 3-(alkoxycarbonyl)allyldimethylsulfonium bromide 3 in the presence of potassium carbonate in acetonitrile at room temperature or by the reaction of compounds 2 with preformed dimethylsulfonium 3-(alkoxycarbonyl)allylides 4 at –78 °C in moderate to good yields. The cis/trans value of the product ranged from 1/1 to 8/1.

Stereocontrolled synthesis of either trans- or cis-trimethylsilylvinyloxiranes via sulfonium ylides

trans- or cis-β-Trimethylsilylvinyloxiranes are prepared by the reaction of aldehydes with a 3-trimethylsilylated dimethylsulfonium allylide under phase-transfer conditions or with a preformed 3-trimethylsilylated diphenylsulfonium allylide in the presence of LiBr, both in excellent yields and high stereoselectivity.

The first efficient preparation of vinylaziridines via an ylide route

A simple and direct method for preparation of vinylaziridines via an ylide route is described; dimethylsulfonium allylides or dimethylsulfonium cinnamylides, produced in situ from the corresponding allylic sulfonium salts and solid potassium hydroxide in acetonitrile at room temperature, react efficiently with N-sulfonylimines to furnish vinylaziridines rapidly with excellent yields.