166773-08-6Relevant articles and documents
N-Heterocyclic carbene-mediated redox condensation of alcohols
Kato, Terumasa,Matsuoka, Shin-Ichi,Suzuki, Masato
supporting information, p. 8569 - 8572 (2016/07/13)
N-Heterocyclic carbenes (NHCs) with a variety of oxidants promote the Mitsunobu-type coupling reactions of alcohols with phenols, carboxylic acids, and phthalimide. Experiments using a chiral alcohol indicate that these reactions proceed via SN1 or SN2 pathways depending on the polarity of the used solvents. The NHCs are consumed as reducing reagents to form their oxides as readily separable byproducts.
PROCESS FOR THE DIMERIZATION OF ACTIVATED OLEFINS
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Page/Page column 14; 15, (2015/12/08)
The present invention relates to a process for the preparation of compounds or a mixture of compounds of the general formulae I.a or I.b wherein R1 is selected from C1-C12-alkyl, C3-C6-cycloalkyl, -C(
Cooperative N-heterocyclic carbene/Br?nsted acid catalysis for the tail-to-tail (co)dimerization of methacrylonitrile
Kato, Terumasa,Matsuoka, Shin-Ichi,Suzuki, Masato
, p. 4484 - 4491 (2014/06/09)
The first tail-to-tail dimerization of methacrylonitrile (MAN) has been realized by the cooperative use of N-heterocyclic carbene (NHC) and Br?nsted acid catalysts, producing 2,5-dimethylhex-2-enedinitrile with the E/Z ratio of 24:76. Although the NHC alo
Aldehyde umpolung by N-heterocyclic carbenes: NMR characterization of the breslow intermediate in its keto form, and a spiro-dioxolane as the resting state of the catalytic system
Berkessel, Albrecht,Elfert, Silvia,Etzenbach-Effers, Kerstin,Teles, J. Henrique
body text, p. 7120 - 7124 (2010/12/18)
Surprises from a classic: The Breslow intermediate of triazolylidene- catalyzed benzoin condensations was characterized for the first time by NMR spectroscopy in its keto form (K, energetic minimum). The hitherto unknown spiro-dioxolane S, generated from
Preparation and application of 1,3,4-triphenyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene, a stable carbene
Enders, Dieter,Breuer, Klaus,Kallfass, Ulrike,Balensiefer, Tim
, p. 1292 - 1295 (2007/10/03)
The title compound 1,3,4-triphenyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene has been prepared in quantitative yield from the corresponding 5-methoxytriazoline precursor by simple thermal decomposition in vacuo via α-elimination of methanol. The carbene is a
Catalytic application of a Ru-alkylidene in the nucleophilic addition of several carboxylic acids on terminal alkynes and the homo-coupling of 1-alkynes
Melis, Karen,De Vos, Dirk,Jacobs, Pierre,Verpoort, Francis
, p. 131 - 136 (2007/10/03)
Thermal treatment of Ru-alkylidene (4) bearing a triazol-5-ylidene (NHC) ligand (2) at 110°C and addition of a terminal alkyne generates a ruthenium vinylidene. The thermolysed Ru-alkylidene catalyses the vinylation and dimerisation of 1-alkynes. The nucleophilic addition of acetic acid on terminal alkynes proceeds smoothly and regioselective towards the Markovnikov addition. The addition reaction can be tuned by changing the acidity of the carboxylic acid. At increasing acidity, higher conversion of the triple bond is obtained and the vinylation/dimerisation ratio increases. The direct coupling between two 1-alkynes shows a reactivity order, which decreases from 1-octyne > 1,7-octadiyne > phenylacetylene > 3,3 dimethyl-1-butyne. The regioselectivity is strongly dependent on the nature of the terminal alkyne.
Catalytic application of a Ru-alkylidene in the nucleophilic addition of several carboxylic acids on terminal alkynes and the homo-coupling of 1-alkynes
Melis, Karen,De Vos, Dirk,Jacobs, Pierre,Verpoort, Francis
, p. 131 - 136 (2015/03/04)
Thermal treatment of Ru-alkylidene (4) bearing a triazol-5-ylidene (NHC) ligand (2) at 110 °C and addition of a terminal alkyne generates a ruthenium vinylidene. The thermolysed Ru-alkylidene catalyses the vinylation and dimerisation of 1-alkynes. The nucleophilic addition of acetic acid on terminal alkynes proceeds smoothly and regioselective towards the Markovnikov addition. The addition reaction can be tuned by changing the acidity of the carboxylic acid. At increasing acidity, higher conversion of the triple bond is obtained and the vinylation/dimerisation ratio increases. The direct coupling between two 1-alkynes shows a reactivity order, which decreases from 1-octyne>1,7-octadiyne>phenylacetylene>3,3 dimethyl-1-butyne. The regioselectivity is strongly dependent on the nature of the terminal alkyne.
Darstellung, Struktur und Reaktivitaet von 1,3,4-Triphenyl-4,5-dihydro-1H-1,2,4-triazol-5-yliden, einem neuen stabilen Carben
Enders, Dieter,Breuer, Klaus,Raabe, Gerhard,Runsink, Jan,Teles, J. Henrique,et al.
, p. 1119 - 1122 (2007/10/02)
Stichworte: Carbene * Cycloadditionen * Heterocyclen * Insertionen