Results 31 to 40 of about 196,557 (349)

On the prevalence of bridged macrocyclic pyrroloindolines formed in regiodivergent alkylations of tryptophan. [PDF]

open access: yes, 2016
A Friedel-Crafts alkylation is described that efficiently transforms tryptophan-containing peptides into macrocycles of varying ring connectivity. Factors are surveyed that influence the distribution of regioisomers, with a focus on indole C3-alkylations
Curtin, Brice H   +5 more
core   +1 more source

Regioselective Alkylation of an Oxonaphthalene-Annelated Pyrrol System

open access: yesMolbank, 2009
The regioselective alkylation of an oxonaphthalene-annelated pyrrole system is reported. The regioselectivity of alkylation can be controlled by the selection of the solvent.
Helmut Spreitzer, Christiane Puschmann
doaj   +1 more source

Oxidative alkylation of (η5-C5Me5)2TiR (R = Cl, Me, Et, CH=CH2, Ph, OMe, N=C(H)tBu) to (η5-C5Me5)2Ti(Me)R by group 12 organometallic compounds MMe2 [PDF]

open access: yes, 1991
Oxidative alkylation of Cp*2TiX (Cp*: η5-C5Me5; X = OMe, Cl, N=C(H)tBu) and Cp* 2TiMe by CdMe2 or ZnMe2 gives diamagnetic Cp*2Ti(Me)X and Cp*2TiMe2 respectively, and cadmium or zinc.
Luinstra, Gerrit A.,, Teuben, Jan H.,
core   +2 more sources

Alkylating Agents Stronger than Alkyl Triflates [PDF]

open access: yesJournal of the American Chemical Society, 2004
A new class of potent electrophilic "R(+)" alkylating agents has been developed using weakly nucleophilic carborane anions as leaving groups. These reagents, R(CHB(11)Me(5)X(6)) (R = Me, Et, and i-Pr; X = Cl, Br), are prepared via metathesis reactions with conventional alkylating agents such as alkyl triflates, using the high oxophilicity of silylium ...
Kato, Tsuyoshi   +4 more
openaire   +4 more sources

Formation of Amphiphilic Molecules from the Most Common Marine Polysaccharides, toward a Sustainable Alternative?

open access: yesMolecules, 2021
Marine polysaccharides are part of the huge seaweeds resources and present many applications for several industries. In order to widen their potential as additives or bioactive compounds, some structural modifications have been studied.
Tiphaine Wong   +6 more
doaj   +1 more source

Study on the Alkylation Reactions of N(7)-Unsubstituted 1,3-Diazaoxindoles

open access: yesMolecules, 2017
The chemistry of the 5,7-dihydro-6H-pyrrolo[2,3-d]pyrimidin-6-one (1,3-diazaoxindole) compound family, possessing a drug-like scaffold, is unexplored. In this study, the alkylation reactions of N(7)-unsubstituted 5-isopropyl-1,3-diazaoxindoles bearing ...
Eszter Kókai   +5 more
doaj   +1 more source

Homoallylglycine residues are superior precursors to orthogonally modified thioether containing polypeptides. [PDF]

open access: yes, 2018
Homoallylglycine N-carboxyanhydride, Hag NCA, monomers were synthesized and used to prepare polypeptides containing Hag segments with controllable lengths of up to 245 repeats.
Deming, Timothy J   +2 more
core   +1 more source

Catalytic Alkylation of Brown Coal and Peat

open access: yesEurasian Chemico-Technological Journal, 2012
The alcohol alkylation of low-grade metamorphic coal and peat in the presence of mineral and organic acids was studied using FTIR, NMR, and GC-MS. The impact of the reaction conditions on the yield of extractable matter was investigated experimentally ...
S. I. Zherebtsov, Z. R. Ismagilov
doaj   +1 more source

Study of synthesis of 2-(2-alkoxyphenyl)-1H-imidazoles. Comparison of oxidative aromatization reactions of imidazolines [PDF]

open access: yes, 2006
The reaction of methyl salicylate with ethane-1,2-diamine has been used to prepare 2-(2-hydroxyphenyl)-1H-imidazoline. This compound was alkylated with alkyl halides to give five new 2-(2-alkoxyphenyl)-1H-imidazolines (alkyl = propyl, isopropyl, isobutyl,
Handlíř, Karel   +4 more
core   +2 more sources

Alkylation of Dihydrofullerenes [PDF]

open access: yesThe Journal of Organic Chemistry, 2002
The fulleride dianions C(60)(2-) and C(70)(2-) were generated by deprotonation of the corresponding hydrogenated fullerenes, 1,2-C(60)H(2) and 1,2-C(70)H(2). These anions were prepared in the presence of a variety of alkylating agents, and mono- or dialkylated products were obtained. Alkylation was not successful with sulfonate ester alkylating agents.
Mark S, Meier   +4 more
openaire   +2 more sources

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