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: These new immobilized anhydrous HF catalysts contain varied amines and nitrogen-containing polymers as complexing agents and represent a new, "green" class of catalyst systems for alkylation reactions, maintaining activity of HF while minimizing its environmental hazards.
Abstract: Isoparaffin−olefin alkylation was investigated using liquid as well as solid onium poly(hydrogen fluoride) catalysts. These new immobilized anhydrous HF catalysts contain varied amines and nitrogen-containing polymers as complexing agents. The liquid poly(hydrogen fluoride) complexes of amines are typical ionic liquids, which are convenient media and serve as HF equivalent catalysts with decreased volatility for isoparaffin−olefin alkylation. Polymeric solid amine:poly(hydrogen fluoride) complexes are excellent solid HF equivalents for similar alkylation acid catalysis. Isobutane−isobutylene or 2-butene alkylation gave excellent yields of high octane alkylates (up to RON = 94). Apart from their excellent catalytic performance, the new catalyst systems significantly reduce environmental hazards due to the low volatility of complexed HF. They represent a new, “green” class of catalyst systems for alkylation reactions, maintaining activity of HF while minimizing its environmental hazards.
101 citations
TL;DR: The chemoselective oxidative α-C(sp(3))-H alkylation/cyclization reaction of N-benzyl carbamates using simple mono-, di-, and trisubstituted olefins provides functionalized N-heterocycles such as oxazinones.
Abstract: Easy does it! The chemoselective oxidative α-C(sp(3))-H alkylation/cyclization reaction of N-benzyl carbamates using simple mono-, di-, and trisubstituted olefins provides functionalized N-heterocycles such as oxazinones. A TEMPO oxoammonium salt serves as the oxidant, making it possible to carry out the reaction at low temperatures. Neither a metal catalyst nor preactivation in the α-position to the nitrogen group are needed.
101 citations
TL;DR: The presence of the two hydroxy groups in the bipyridine ligand is crucial for the catalytic activity as discussed by the authors, and the presence of these two hydroxyl groups has been shown to be crucial for catalytic performance.
Abstract: The presence of the two hydroxy groups in the bipyridine ligand are crucial for the catalytic activity.
101 citations
TL;DR: Diastereoselective alkylation de lithio enamines obtenues a partir d'α-alkyl β-cetoesters et du (S)-valinate de t-butyle as discussed by the authors.
Abstract: Diastereoselective alkylation de lithio enamines obtenues a partir d'α-alkyl β-cetoesters et du (S)-valinate de t-butyle
101 citations
TL;DR: A new organocatalytic strategy is described in which in-situ generated aza-para-quinone methides are employed as the alkylating reagent, and the intermolecular C-N bond formation with various indole and carbazole nucleophiles proceeded efficiently under mild conditions with excellent enantioselectivity and functional-group compatibility.
Abstract: Catalytic asymmetric N-alkylation of indoles and carbazoles represents a family of important but underdeveloped reactions. Herein, we describe a new organocatalytic strategy in which in situ generated aza-para-quinone methides are employed as the alkylating reagent. With the proper choice of a chiral phosphoric acid and an N-protective group, the intermolecular C−N bond formation with various indole and carbazole nucleophiles proceeded efficiently under mild conditions with excellent enantioselectivity and functional-group compatibility. Control experiments and kinetic studies provided important insight into the reaction mechanism.
101 citations