Topic
Alkylation
About: Alkylation is a research topic. Over the lifetime, 29915 publications have been published within this topic receiving 464944 citations. The topic is also known as: alkylation reaction.
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TL;DR: In this article, N-Alkyl carbamates were obtained with good to excellent yields by clean and mild transcarboxylation of several amines with the previously synthesized DBU-CO2 complex and subsequent O-alkylation.
118 citations
TL;DR: An ortho-fluoro substituent on the benzyl group in the quaternary ammonium salt dramatically increased the enantioselectivity in the alkylation of glycine anion equivalent.
118 citations
TL;DR: A novel method for the C-H functionalization of carbamate-protected secondary amines via α-carbamyl radicals generated using photoredox catalysis is described, which was able to showcase the utility of this methodology through the enantioselective synthesis of the indolizidine alkaloid, (+)-monomorine I.
Abstract: Strategies for the direct C–H functionalization of amines are valuable as these compounds comprise a number of pharmaceuticals, agrochemicals and natural products. This work describes a novel method for the C–H functionalization of carbamate-protected secondary amines via α-carbamyl radicals generated using photoredox catalysis. The use of the highly oxidizing, organic acridinium photoredox catalyst allows for direct oxidation of carbamate-protected amines with high redox potentials to give the corresponding carbamyl cation radical. Following deprotonation, the resultant open-shell species can be intercepted by a variety of Michael acceptors to give elaborate α-functionalized secondary amines. The reaction proceeds under mild conditions without the requirement of exogenous redox mediators or substrate prefunctionalization. Additionally, we were able to showcase the utility of this methodology through the enantioselective synthesis of the indolizidine alkaloid, (+)-monomorine I.
118 citations
TL;DR: A variety of secondary amines could be alkylated by allowing them to react with aldehydes and PMHS in the presence of an iridium catalyst to afford the corresponding tertiary amines in good to excellent yields.
Abstract: An efficient methodology for the reductive alkylation of secondary amine with aldehyde and Et3SiH using an iridium complex as a catalyst has been developed. For example, treatment of dibutylamine with butyraldehyde and Et3SiH (a 1:1:1 molar amount of amine, aldehyde, and silane) in 1,4-dioxane at 75 °C under the influence of a catalytic amount of [IrCl(cod)]2 gave tributylamine in quantitative yield. In this reaction, no reduction of aldehyde took place. It was found that IrCl3, which is a starting material for preparation of iridium complexes such as [IrCl(cod)]2, acts as an efficient catalyst for the present reductive alkylation of amine. In addition, a cheaper, easy-to-handle, and environmentally friendly reducing reagent such as polymethylhydrosiloxane (PMHS) in place of Et3SiH was also useful. Thus, a variety of secondary amines could be alkylated by allowing them to react with aldehydes and PMHS in the presence of an iridium catalyst to afford the corresponding tertiary amines in good to excellent y...
118 citations
118 citations