Regioselective Intermolecular Allylic C−H Amination of Disubstituted Olefins via Rhodium/π‐Allyl Intermediates

Abstract

Am ethod for catalytic intermolecular allylic C À H amination of trans-disubstituted olefins is reported. The reaction is efficient for ar ange of common nitrogen nucleophiles bearing one electron-withdrawing group,a nd proceeds under mild reaction conditions.Good levels of regioselectivity are observed for awide range of electronically diverse trans-balkylstyrene substrates.

Allylic Amination of Alkenes with Iminothianthrenes to Afford Alkyl Allylamines

“… 1 Currently, two major strategies are available for direct allylic C–H amination: 8 Reactions can proceed through π-allylmetal species followed by attack with N-nucleophiles ( Scheme 1 A). 9 The White 9c , 9d and Liu 9e groups independently reported palladium-catalyzed allylic C–H amination with sulfonylcarbamates. The scope of the nitrogen-based nucleophiles was further expanded to N-heteroarenes, 9f , 9g sulfonamides, 9h , 9i and carboxamides.…”

A site-selective amination catalyst discriminates between nearly identical C–H bonds of unsymmetrical disubstituted alkenes

“…Selective allylic C–H functionalizations provide a platform for the construction of valuable building blocks from chemical feedstocks 18 , 19 , 20 , 21 , 22 . Currently, intermolecular allylic C–H amination reactions are mostly limited to alkenes with only one distinct set of allylic protons 23 , 24 , 25 , 26 , 27 , 28 , 29 , due to the lack of methods to distinguish similar allylic positions. Two important exceptions are Dauban’s work 30 31 of Rh(II)-catalyzed outer-sphere nitrene insertion preferring methylene over methyl C–H bonds and Tambar’s two-step protocol 32 where an asymmetric ene-type transformation of cis -olefins was demonstrated to distinguish between two allylic positions ( Fig.…”

Regio‐ and Diastereoselective Rhodium‐Catalyzed Allylic Substitution with Unstabilized Benzyl Nucleophiles

“…as pre-catalysts is rare in allylic substitution reactions,a lbeit they have been deployed in processes that generate am etal-allyl intermediate via allylic CÀHa ctivation. [22] Remarkably,w ef ound that the commercially available and bench-stable rhodium(III) chloride trihydrate is capable of delivering the allylic benzylation product 2a with similar efficiency and selectivity to the aforementioned rhodium(I) pre-catalysts. [20] Table 1o utlines the development of ah ighly regioselective allylic benzylation using rhodium(III) chloride as the precatalyst.…”