Preparation and Reactivity of Allyl N-[(Arylsulfonyl)oxy]carbamates, New Reagents for Electrophilic Transfer of an NHAlloc Group

摘要

Carbon-nitrogen bonds are usually formed by attack of nucleophilic nitrogen on an eiectrophilic carbon bearing a leaving group, via an SN_2-type reaction. Since the discovery of the polarity reversal process by Sheverdina and Kocheskov, in combinationwith the development of new metalation procedures, increased attention has been focused on the development of eiectrophilic reagents for the animation of carbon nucleophiles. This type of "Umpolang" animation process has also been modified for the construction of chiral amines by the reaction of eiectrophilic animating reagents with chiral enolates. More recently, Oppolzer et al. have reported a chiral α-chloro-α-nitroso reagent which reacted with prochiral ketone enolates with high enantiofacial differentiation.