Hydroxoiridium‐Catalyzed Hydroalkylation of Terminal Alkenes with Ureas by C(sp³)−H Bond Activation

Abstract

Direct alkylation of a methyl group, on di- and trisubstituted ureas, with terminal alkenes by C(sp )-H bond activation proceeded in the presence of a hydroxoiridium/bisphosphine catalyst to give high yields of the corresponding addition products. The hydroxoiridium/bisphosphine complex generates an amidoiridium intermediate by reaction with ureas having an N-H bond.

A comprehensive overview of directing groups applied in metal-catalysed C–H functionalisation chemistry

“…A third alkylation protocol was reported by Nishimura and co-workers. 264 Mainly starting materials of the type N , N ′-diaryl- N -methylurea were used. Alkylation took place at the N -methyl and not on the arene system (!…”

Exploiting Natural Complexity: Synthetic Terpenoid‐Alkaloids by Regioselective and Diastereoselective Hydroaminoalkylation Catalysis

“…[7][8][9][10] Furthermore, diastereoselective hydroaminoalkylation has not been explored. Late transition metal variants of this reaction show improved functional group tolerance, but require directing/protecting groups to promote CÀ H activation (Figure 1b), [11] while photocatalytic hydroaminoalkylation is an exciting approach that uses multiple catalytic systems and specialized reaction setups. [12] An alternative strategy to access these products employs tandem hydroformylation-reductive amination, to give the linear regioisomer.…”

Alkyl Halides as Both Hydride and Alkyl Sources in Catalytic Regioselective Reductive Olefin Hydroalkylation

“…Accordingly, hydroalkylations across aliphatic olefins have been devised, although the vast majority involved linear-selective additions ( Fig.1a). Of these cases, either a limited range of ureas 34 , organometallic reagents [35][36] or carbonyl compounds [37][38][39] were employed as nucleophiles, or an exogenous protic source 40 or hydrosilane/base reagent [41][42][43][44][45] is needed to (i) promote protodemetallation or (ii) generate the requisite metal-hydride species. To date, highly Markovnikov-selective hydroalkylations of aliphatic -systems have been largely achieved with 1,1-disubstituted/trisubstituted alkenes and primary haloalkanes through a Mn/Ni dual catalytic metal-hydride hydrogen atom transfer approach 46 , or with olefins linked to a tridendate directing group and 1,3-dicarbonyl nucleophiles using a Pd-based catalyst 40 ( Fig.1b).…”