نتایج جستجو برای: alkylation

تعداد نتایج: 5091  

Journal: :Journal of the American Chemical Society 2012
P Andrew Evans Samuel Oliver Jungha Chae

A highly regio- and stereospecific rhodium-catalyzed allylic alkylation of tertiary allylic alcohol derivatives with a cyanohydrin pronucleophile is described. This direct and operationally simple protocol provides a fundamentally novel approach toward the synthesis of α-quaternary substituted ketones and circumvents many of the inherent problems associated with conventional enolate alkylation ...

Journal: :Journal of the American Chemical Society 2010
Barry M Trost Lara C Czabaniuk

Herein we report palladium-catalyzed asymmetric benzylic alkylation with 3-aryl oxindoles as prochiral nucleophiles. Proceeding analogously to asymmetric allylic alkylation, asymmetric benzylation occurs in high yield and enantioselectivity for a variety of unprotected 3-aryl oxindoles and benzylic methyl carbonates using chiral bisphosphine ligands. This methodology represents a novel asymmetr...

Journal: :Nucleic acids research 1992
K Kido H Inoue E Ohtsuka

Antisense oligodeoxyribonucleotides (15mers), containing a 2-(N-iodoacetylaminoethyl)thio-adenine, were synthesized and tested for their ability to cleave complementary DNAs (21mers). Cleavage of the target DNAs was done by alkylation followed by treatment with piperidine, and the positions of the alkylated sites were estimated by identification of the cleaved products. By using several combina...

2017
Jennifer J Jordan Sophea Chhim Carrie M Margulies Mariacarmela Allocca Roderick T Bronson Arne Klungland Leona D Samson Dragony Fu

Regulated necrosis has emerged as a major cell death mechanism in response to different forms of physiological and pharmacological stress. The AlkB homolog 7 (ALKBH7) protein is required for regulated cellular necrosis in response to chemotherapeutic alkylating agents but its role within a whole organism is unknown. Here, we show that ALKBH7 modulates alkylation-induced cellular death through a...

Journal: :Dalton transactions 2010
Eva Hevia Alan R Kennedy Jan Klett Zoe Livingstone Matthew D McCall

A systematic study of the stoichiometric alkylation reactions of 2,2,2-trifluoroacetophenone 1 with [ZnR(2)(TMEDA)] (R= Me, Et, (t)Bu, CH(2)SiMe(3); TMEDA= N,N,N',N'-tetramethylethylenediamine) monitored by (1)H and (19)F NMR spectroscopy is presented. For R = Me, Et the alkylation products alkyl(alkoxides) [(TMEDA)Zn(R){OC(CF(3))(R)Ph}] (R = Me, 2: Et, 3) are obtained as the single products of...

2016
Alfeu Zanotto-Filho Ravi Dashnamoorthy Eva Loranc Luis H T de Souza José C F Moreira Uthra Suresh Yidong Chen Alexander J R Bishop

Alkylating agents are a key component of cancer chemotherapy. Several cellular mechanisms are known to be important for its survival, particularly DNA repair and xenobiotic detoxification, yet genomic screens indicate that additional cellular components may be involved. Elucidating these components has value in either identifying key processes that can be modulated to improve chemotherapeutic e...

2017
Rong Zhou Haiwang Liu Hairong Tao Xingjian Yu Jie Wu

Despite notable recent efforts, a catalytic and convenient strategy for the direct alkylation of unactivated allylic or benzylic sp C–H bonds remains a formidable challenge facing the synthesis community. We herein report an unprecedented allylic/benzylic alkylation using only an organo-photoredox catalyst, which enables coupling of a broad scope of alkenes/arenes and electron-deficient alkenes...

Journal: :Molecules 2018
Carla Boga Silvia Bordoni Lucia Casarin Gabriele Micheletti Magda Monari

The reaction between bis(2-benzothiazolyl)ketone and vinyl Grignard reagents bearing different substituents on the vinyl moiety gave the product derived from attack on the carbonylic carbon- and/or oxygen-atom. The regioselectivity of the attack depends on the kind of substituents bound to the vinylic carbon atoms and on their relative position. The reaction between vinylmagnesium bromide and 2...

Journal: :The Biochemical journal 1974
G Moore R R Crichton

Escherichia coli ribosomes were treated with a number of different aldehydes of various sizes in the presence of NaBH(4). After incorporation of either (3)H or (14)C, the ribosomal proteins were separated by two-dimensional polyacrylamide-gel electrophoresis and the extent of alkylation of the lysine residues in each protein was measured. The same pattern of alkylation was observed with the fou...

2002
Gaurav Chaturvedi

The alkylation process is an important reaction used in refineries to upgrade light olefins and isobutene into a much more highly valued gasoline component. The primary alkylation reaction involves the reaction of isobutene with a light olefin such as butylenes, in the presence of strong acid catalyst to form the high octane. A problem of long standing is to determine the optimal operating cond...

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