Radical [3 + 2] Annulation of N-Allyl-N-chlorotosylamide with Alkenes via Atom-Transfer Process

Abstract

[reaction: see text]. A radical [3+2] annulation reaction with an N-centered radical has been developed. The reaction of alkenes with N-allyl-N-chlorotosylamide yields the corresponding pyrrolidine derivatives in good yields in the presence of Et3B as a radical initiator.

Harnessing Energy‐Transfer in N‐Centered Radical‐Mediated Synthesis of Pyrrolidines

“…In the case of 17 , the sterically more hindered cis isomer is the major isomer, which is again consistent with the Beckwith–Houk model . It is noteworthy that in a related [3+2] cycloaddition reported by Tsuritani, Shinokubo, and Oshima, the authors reported a 68:32 d.r . in a similar reaction albeit with a considerable lower yield of 28%.…”

Intermolecular radical carboamination of alkenes

“…In 2001, Oshima and co-workers reported an elegant radical [3+2] annulation of alkenes with N-allyl-N-chlorotosylamide (1) as N-radical precursor for the preparation of pyrrolidine derivatives 2 (Scheme 2). 46 This cascade proceeds through a radical chain process and features a broad scope with respect to the alkene component. Hence, aliphatic alkenes, styrenes, vinyl acetates and even benzofuran are eligible acceptors yielding the corresponding multi-substituted pyrrolidines in high yields albeit with low diastereoselectivity.…”

Intermolecular addition reactions of N-alkyl-N-chlorosulfonamides to unsaturated compounds

“…Other procedures for the synthesis of these compounds including N -chlorination with an fivefold excess of Oxone ® in the presence of NaCl/Al 2 O 3 [ 35 ] or deprotonation and reaction with NCS [ 36 – 37 ] did not lead to higher or led in distinctly lower yields to the N -chloro compounds.…”