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.
Papers published on a yearly basis
Papers
More filters
••
TL;DR: The reaction between NEM and two proteins lysozyme and ribonuclease A results, under certain experimental conditions, in the alkylation of ϵ-amino and imidazole groups as discussed by the authors.
249 citations
••
248 citations
••
248 citations
••
TL;DR: A new protein modification reaction has been developed based on a palladium-catalyzed allylic alkylation of tyrosine residues that provides convenient access to synthetic lipoproteins.
Abstract: A new protein modification reaction has been developed based on a palladium-catalyzed allylic alkylation of tyrosine residues. This technique employs electrophilic pi-allyl intermediates derived from allylic acetate and carbamate precursors and can be used to modify proteins in aqueous solution at room temperature. To facilitate the detection of modified proteins using SDS-PAGE analysis, a fluorescent allyl acetate was synthesized and coupled to chymotrypsinogen A and bacteriophage MS2. The tyrosine selectivity of the reaction was confirmed through trypsin digest analysis. The utility of the reaction was demonstrated by using taurine-derived carbamates as water solubilizing groups that are cleaved upon protein functionalization. This solubility switching technique was used to install hydrophobic farnesyl and C(17) chains on chymotrypsinogen A in water using little or no cosolvent. Following this, the C(17) alkylated proteins were found to associate with lipid vesicles. In addition to providing a new protein modification strategy targeting an under-utilized amino acid side chain, this method provides convenient access to synthetic lipoproteins.
247 citations
••
TL;DR: This is the first colloidal system shown to display such a high enantioselectivity besides the well-known Pt/cinchonidine system.
Abstract: Palladium nanoparticles (4 nm, fcc) were prepared through decomposition of [Pd2(dba)3] by H2 in the presence of a chiral xylofuranoside diphosphite. These particles catalyze the allylic alkylation of rac-3-acetoxy-1,3-diphenyl-1-propene with dimethyl malonate leading to an almost total conversion of the (R) enantiomer and almost no reaction with the (S). This gives rise to 97% ee for the alkylation product and a kinetic resolution of the substrate recovered with ca. 90% ee. This behavior was compared to that of a molecular catalyst at various dilutions, and the differences between the two systems are discussed. This is the first colloidal system shown to display such a high enantioselectivity besides the well-known Pt/cinchonidine system.
246 citations