Chelation-assisted alkylation of benzylamine derivatives by Ru0 catalyst
作者:Chul-Ho Jun
DOI:10.1039/a801298i
日期:——
N-Benzyl-N-(3-methyl-2-pyridyl)amine 1 reacts with various alkenes via sp3 C–H bond cleavage by catalytic Ru3(CO)12 to give the corresponding alkylated products.
Investigations of the generality of quaternary ammonium salts as alkylating agents in direct C–H alkylation reactions: solid alternatives for gaseous olefins
C–H alkylation reactions using short chain olefins as alkylating agents could be operationally simplified on the lab scale by using quaternary ammonium salts as precursors for these gaseous reagents: Hofmann elimination delivers in situ the desired alkenes with the advantage that the alkene concentration in the liquid phase is high. In case a catalytic system did not tolerate the conditions for Hofmann
Quaternary Ammonium Salts as Alkylating Reagents in C–H Activation Chemistry
作者:Manuel Spettel、Robert Pollice、Michael Schnürch
DOI:10.1021/acs.orglett.7b01946
日期:2017.8.18
of benzylic amines via C(sp3)–H activation using quaternaryammoniumsalts as alkyl source is described. The reaction proceeds via in situ formation of an olefin via Hofmann elimination, which is the actual alkylating reagent. This represents an operationally simple method for substituting gaseous and liquid olefins with solid quaternaryammoniumsalts as alkylating reagents, which is transferable to
Investigations into the Kinetic Modeling of the Direct Alkylation of Benzylic Amines: Dissolution of K<sub>2</sub>CO<sub>3</sub> Is Responsible for the Observation of an Induction Period
作者:Robert Pollice、Michael Schnürch
DOI:10.1021/acs.joc.5b01335
日期:2015.8.21
Investigations into the kinetics of a Rh(I)-catalyzed direct C-H alkylation of benzylic amines with alkenes revealed that K2CO3, which is effectively insoluble in the reaction mixture, is only needed in the beginning of the reaction. During the concomitant induction period, K2CO3 is proposed to dissolve to a vanishingly small extent and the Rh-precatalyst irreversibly reacts with dissolved K2CO3 to form the active catalyst. The duration of this induction period is dependent on the molar loading, the specific surface, the H2O content of K2CO3, and agitation, and these dependences can be rationalized based on a detailed kinetic model.
Rhodium-catalyzed direct alkylation of benzylic amines using alkyl bromides
Within this contribution, the development and substrate scope evaluation of a direct alkylation protocol of the C(sp3)–H bond of benzylic aminesusing alkyl bromides is reported. This pyridine-directed method is initiated by elimination of the alkyl bromide to a terminal olefin, which is then the true alkylating agent. Graphical abstract