Lithiation-electrophilic trapping of N-sulfonyl-activated ethylene aziridines.

Deprotection of Sulfonyl Aziridines

The deprotection of the chiral N-sulfonyl aziridines 1-3 has been studied under different desulfonylation conditions. Two methods for the efficient deprotection of 2-benzyl-, 2-phenyl-, and 2-carboxyl-N-sulfonylaziridines were found. The desulfonylation with lithium and a catalytic amount of di-tert-butyl biphenyl in THF at -78 °C led to the corresponding NH aziridines with yields up to 85%. Al...

Aza-pinacol rearrangement: acid-catalyzed rearrangement of aziridines to imines.

A series of di-, tri-, and tetra-substituted N-tosylaziridines [N-(toluene-p-sulfonyl)aziridines] 1, prepared by aziridination of the corresponding alkenes with N-[(tolyl-p-sulfonyl)imino]phenyliodinane (TsN = IPh), was found to undergo a BF3-catalyzed rearrangement (aza-pinacol rearrangement) under mild conditions to give the corresponding N-tosylimines 2 generally in satisfactory yields.

Highly regioselective synthesis of functionalized aminonitriles starting from 2-(ω-cyanoalkyl)aziridines

1-arylmethyl-2-(bromomethyl)aziridines were transformed into the corresponding 2(cyanomethyl)aziridines and 2-(2-cyanoethyl)aziridines upon treatment with potassium cyanide in DMSO and α-lithiated trimethylsilylacetonitrile in THF, respectively. Further elaboration of 1-arylmethyl-2-(cyanomethyl)aziridines afforded 4-amino-2-butenenitriles, 3,4diaminobutanenitriles and 2-aminocyclopropanecarbon...

Lithiation-induced migrations from nitrogen to carbon in terminal aziridines.

Ring-opening reaction of Bus- and SES-protected aziridines using lithiated dithianes.

The scope and limitation of the ring-opening reaction of sulfonyl-activated aziridines using lithiated dithianes was investigated. Nucleophilic attack of lithiated dithianes on aziridines containing tert-butylsulfonyl (Bus) and 2-(trimethylsilyl)ethylsulfonyl (SES) demonstrated efficient ring cleavage to yield beta-amino carbonyl equivalents, gamma-lactam and syn- and anti-1,5-aminoalcohols. Th...