126256-02-8Relevant academic research and scientific papers
Double coordination and activation ability of methylalumoxane (MAO) for hetero functionality: Pivotal role as polymerization cocatalyst
Hanawa, Hideo,Abe, Noriko,Maruoka, Keiji
, p. 5365 - 5368 (1999)
A new insight in the crucial role of methylalumoxane (MAO) as polymerization cocatalyst has been demonstrated by using typical carbonyl reduction and electrophilic alkylation by comparison with various MAO analogues, (Me2Al)2O, MeAl(OPr(i))2, and Me2AlOPr(i). Furthermore, the high ligand-abstraction ability of MAO for a zirconocene complex is evaluated by the allylzirconation of internal alkyne, where MAO was found to be more satisfactory as cocatalyst than (Me2Al)2O and Me3Al in terms of reactivity.
An increased understanding of enolate additions under mechanochemical conditions
Hopgood, Heather,Mack, James
, (2017/06/08)
Very little is known about enolate addition chemistry under solver-free mechanochemical conditions. In this report, we investigated the ability to selectively form products arising from the primary, secondary, and tertiary enolates under solvent-free conditions. Using potassium tert-butoxide as the base and primary, secondary, and tertiary electrophiles, we were able to generate various enolate addition products including, 1,3,3,3-Tetraphenyl-2,2-dimethyl-1-propanone; a molecule we did not observe under traditional solution-based conditions.
Building Congested Ketone: Substituted Hantzsch Ester and Nitrile as Alkylation Reagents in Photoredox Catalysis
Chen, Wenxin,Liu, Zheng,Tian, Jiaqi,Li, Jin,Ma, Jing,Cheng, Xu,Li, Guigen
, p. 12312 - 12315 (2016/10/07)
For the first time, 4-alkyl Hantzsch esters were used to construct molecules with all-carbon quaternary centers by visible light-induced photoredox catalysis via transfer alkylation. Up to a 1500 h-1 turnover frequency was achieved in this reaction. Reactions of 4-alkyl Hantzsch nitriles as tertiary radical donors joined two contiguous all-carbon quaternary centers intermolecularly, and this chemistry was used to synthesize a common precursor of a class of hydroxysteroid dehydrogenase inhibitors.
Thermal Decomposition of 3,3,5-Trisubstituted-4,4-dimethyl-4,5-dihydro-5-hydroperoxy-3H-pyrazoles: Route to β,γ-Unsaturated Ketones
Baumstark, Alfons L.,Vasquez, Pedro C.
, p. 113 - 117 (2007/10/02)
The thermal decomposition of a series of cyclic α-azo hydroperoxides (3,3,5-R1, R2, R3-4,4-dimethyl-4,5-dihydro-5-hydroperoxy-3H-pyrazoles; 2a R1 = R2 = R3 = Ph; 2b R1= R3 = Ph, R2 = Me; 2c R1 = R3 = p-Anisyl, R2 = Me; 2d R1 = R2 = Me, R3 = Ph; 2e R1 = R3 = Me, R2 = Ph), synthesized by oxidation of the corresponding 3,4-dihydro-2H-pyrazoles, proceeded smoothly with evolution of nitrogen.The relative stability series was found to be 2a > 2c ca. 2b > 2d > 2e.For 2a, the products were 1,4,4-triphenyl-2,2-dimethylpropanone and 1,1-dimethyl-2,2-diphenylethylene.For 2b-e,m β,γ-unsaturated ketones were obtained as the major products in ca. 60percent yield from the thermolyses.The products are consistent with a free-radical mechanism involving initial homolysis of the O-O bond followed by loss of nitrogen to yield a free-radical beta to the carbonyl group.For 2a, β-scission and hydrogen-atom abstraction of the hydroperoxy proton by the β-keto radical (induced decomposition) are the major pathways leading to products.For 2b-c, abstraction of a γ-hydrogen atom of the β-keto radicals by hydroxy radical accounts for the formation of the β,γ-unsaturated compounds as the major product.
Arene Hydrides, 8. - SET vs. Nucleophilic Attack in Reactions of α-Bromoisobutyrophenone with Carbanions. Fragmentation of the Anion of Tetrahydrobianthracene
Werry, Juergen,Stamm, Helmut,Sommer, Andreas
, p. 1553 - 1562 (2007/10/02)
SET is the main reaction pathway between α-bromoisobutyrophenone (1) and the carbanions 7a-j- of diarylmethanes or disubstituted acetonitriles: 7- 7. + e and e + 1 Br- PhCOCMe2. (3).Main secon
