13019-19-7Relevant academic research and scientific papers
A new experimental protocol for intrazeolite photooxidations. The first product-based estimate of an upper limit for the intrazeolite singlet oxygen lifetime
Pace, Andrea,Clennan, Edward L.
, p. 11236 - 11237 (2002)
The intrazeolite photooxidations of several alkenes have been examined in hexane and in perfluorohexane slurries. The ability of perfluorohexane to increase the affinity of alkenes for the interior of the zeolite was documented. The nearly identical reaction rates in the two slurry solvents are attributed to a leveling of the singlet oxygen lifetime by the zeolite framework. A consideration of the rates of the various intrazeolite processes was used to estimate an upper limit for the intrazeolite lifetime of singlet oxygen. Copyright
Regioselective formation of silylated cyclobutenes by the photochemical [2+2] cycloaddition of 2(5H)-furanones to trialkylsilylacetylenes
D'Annibale, Andrea,D'Auria, Maurizio,Mancini, Giovanna,Pace, Alessio Daniel,Racioppi, Rocco
, p. 785 - 791 (2012)
Enantiopure 5-alkyl-4-methyl-2(5H)-furanones reacted by [2+2] photochemical cycloaddition with several trialkylsilylacetylenes to afford regioselectively 3-oxabicyclo[3.2.0]hept-6-en-2-ones silylated at the vinylic C-7 atom. The possible reasons for such regioselectivity are discussed. The anti/syn stereoselectivity of the photocycloaddition depends on the nature of the alkyl group on the silicon atom in the starting silylacetylenes. The photochemical cycloaddition of 2(5H)-furanones to trialkylsilylacetylenes regioselectively afforded cyclobutenes fused with furanone systems. Copyright
Palladium/Norbornene-Catalyzed ortho Aliphatic Acylation with Mixed Anhydride: Selectivity and Reactivity
Xu, Shibo,Jiang, Julong,Ding, Linlin,Fu, Yao,Gu, Zhenhua
, p. 325 - 328 (2018)
A palladium/norbornene-catalyzed ortho acylation for the efficient synthesis of functionalized alkyl aryl ketones is reported. Studies on the electronic and steric properties of mixed aryl anhydrides indicated that the cross-coupling favored with the elec
Kinetic Resolution of Allyltriflamides through a Pd-Catalyzed C-H Functionalization with Allenes: Asymmetric Assembly of Tetrahydropyridines
González, José Manuel,Cendón, Borja,Mascare?as, José Luis,Gulías, Moisés
supporting information, p. 3747 - 3752 (2021/04/06)
Enantioenriched, six-membered azacycles are essential structural motifs in many products of pharmaceutical or agrochemical interest. Here we report a simple and practical method for enantioselective assembly of tetrahydropyridines, which is paired to a ki
Palladium-catalyzed intramolecular reductive olefin hydrocarbonation: Benzylic hydrogen serving as a new hydrogen donor
Dong, Xu,Cui, Jie,Song, Jian,Han, Ying,Liu, Qing,Dong, Yunhui,Liu, Hui
supporting information, p. 4903 - 4906 (2017/07/11)
A palladium-catalyzed intramolecular hydrocarbonation of unactivated alkenes was achieved, in which toluene is used as a hydrogen donor for the first time. The radical transfer hydrogenation is designed and realized based on the Bond Dissociation Energy (
Copper Hydride Catalyzed Reductive Claisen Rearrangements
Wong, Kong Ching,Ng, Elvis,Wong, Wing-Tak,Chiu, Pauline
supporting information, p. 3709 - 3712 (2016/03/08)
An efficient reductive Claisen rearrangement, catalyzed by in situ generated copper hydride and stoichiometric in diethoxymethylsilane, has been developed. Yields of up to 95 ;% with good to excellent diastereoselectivities were observed in this reaction. Mechanistic studies showed that the stereospecific rearrangement proceeded via a chair transition state of (E)-silyl ketene acetals as intermediates and not via the copper enolates.
Zeolite matrix assisted decomposition of singlet oxygen sensitizers during photooxidation
Shailaja,Sivaguru,Ramamurthy
, p. 197 - 205 (2016/11/16)
Thiazine dyes such as thionine, methylene blue and methylene green were exchanged within monovalent cation exchanged Y zeolites. Depending on the water content the dye molecules exist as either monomer (‘dry’) or dimer (‘wet’). The monomeric dye is effect
Highly diastereoselective hydrosilylations of allylic alcohols
McLaughlin, Mark G.,Cook, Matthew J.
supporting information, p. 3501 - 3504 (2014/03/21)
The highly syn-selective hydrosilylation of allylic alcohols was developed which, following oxidation, provided 1,3 alcohols containing two contiguous stereocentres. Through judicious choice of silane the complementary anti-selective hydrosilylation was a
Highly regioselective control of 1,2-addition of organolithiums to α,β-unsaturated compounds promoted by lithium bromide in 2-methyltetrahydrofuran: A facile and eco-friendly access to allylic alcohols and amines
Pace, Vittorio,Castoldi, Laura,Hoyos, Pilar,Sinisterra, José Vicente,Pregnolato, Massimo,Sánchez-Montero, Ma. José
supporting information; experimental part, p. 2670 - 2675 (2011/04/23)
Very high regioselective 1,2-addition of organolithiums to α,α-unsaturated carbonyl-like compounds (ketones, aldehydes, and imines) in the presence of LiBr was achieved by carrying out reactions in the sustainable solvent 2-methyltetrahydrofuran. Excellent yields (in isolated product) of allylic alcohols and allylic amines were recovered under a simple experimental procedure at 0 °C.
Stereoselective synthesis of trisubstituted olefins by a directed allylic substitution strategy
Schmidt, Yvonne,Breit, Bernhard
supporting information; experimental part, p. 11780 - 11788 (2011/11/06)
New methodology for the stereoselective synthesis of trisubstituted olefins is presented. The use of ortho-diphenylphosphanyl benzoate (o-DPPB) as a directing leaving group for copper-mediated allylic substitution with Grignard reagents allowed for the stereoselective construction of a wide range of E olefins, without the need for an adjacent electron-withdrawing group. Our modular three-step approach toward trisubstituted alkenes commenced with geminal α-methylene aldehydes. Addition of an organometallic reagent and introduction of the o-DPPB group by esterification was followed by the o-DPPB-directed copper-mediated allylic substitution with a Grignard reagent to furnish stereodefined trisubstituted olefins. Additionally, incorporation of a stereocenter from the chiral pool allowed the preparation of an enantiomerically pure olefin that bore three alkyl substituents in high E/Z selectivity.
