4761-26-6Relevant articles and documents
Zeolite mediated Michael addition of 1,3-dicarbonyl compounds and thiols
Sreekumar,Rugmini,Padmakumar, Raghavakaimal
, p. 6557 - 6560 (1997)
Zeolites, an environmentally attractive solid catalyst, proves to be an efficient catalyst for Michael addition of several 1,3-dicarbonyl compounds and thiols as donors with methyl vinyl ketone, acrolein and methyl acrylate as acceptors without any solvent are described.
Synthesis of ((3R,6R)-6-Methylpiperidin-3-yl)methanol via Biocatalytic Transamination and Crystallization-Induced Dynamic Resolution
Chung, John Y. L.,Marcune, Benjamin,Strotman, Hallena R.,Petrova, Rositza I.,Moore, Jeffrey C.,Dormer, Peter G.
, p. 1418 - 1423 (2015)
An asymmetric synthesis of orexin receptor antagonist MK-6096 piperidine core, ((3R,6R)-6-methylpiperidin-3-yl)methanol (3), is described. The target is synthesized in four steps and 40% overall yield from methyl vinyl ketone and diethyl malonate. The key
Metal-dioxidoterephthalate MOFs of the MOF-74 type: Microporous basic catalysts with well-defined active sites
Valvekens, Pieterjan,Vandichel, Matthias,Waroquier, Michel,Van Speybroeck, Veronique,De Vos, Dirk
, p. 1 - 10 (2014/07/21)
The hybrid frameworks M2dobdc (dobdc4- = 2,5-dioxidoterephthalate, M2+ = Mg2+, Co2+, Ni2+, Cu2+ and Zn2+), commonly known as CPO-27 or MOF-74, are shown to be active catalysts in base-catalyzed reactions such as Knoevenagel condensations or Michael additions. Rather than utilizing N-functionalized linkers as a source of basicity, the intrinsic basicity of these materials arises from the presence of the phenolate oxygen atoms coordinated to the metal ions. The overall activity is due to a complex interplay of the basic properties of these structural phenolates and the reactant binding characteristics of the coordinatively unsaturated sites. The nature of the active site and the order of activity between the different M 2dobdc materials were rationalized via computational efforts; the most active material, both in theory and in experiment, is the Ni-containing variant. The basicity of Ni2dobdc was experimentally proven by chemisorption of pyrrole and observation by IR spectroscopy.
Base catalytic activity of alkaline earth MOFs: A (micro)spectroscopic study of active site formation by the controlled transformation of structural anions
Valvekens,Jonckheere,De Baerdemaeker,Kubarev,Vandichel,Hemelsoet,Waroquier,Van Speybroeck,Smolders,Depla,Roeffaers,De Vos
, p. 4517 - 4524 (2015/02/19)
A new method has been developed for generating highly dispersed base sites on metal-organic framework (MOF) lattices. The base catalytic activity of two alkaline earth MOFs, M2(BTC)(NO3)(DMF) (M = Ba or Sr, H3BTC = 1,3,5-benzenetricarboxylic acid, DMF = N,N-dimethylformamide) was studied as a function of their activation procedures. The catalytic activity in Knoevenagel condensation and Michael addition reactions was found to increase strongly with activation temperature. Physicochemical characterization using FTIR, 13C CP MAS NMR, PXRD, XPS, TGA-MS, SEM, EPR, N2physisorption and nitrate content analysis shows that during activation, up to 85% of the nitrate anions are selectively removed from the structure and replaced with other charge compensating anions such as O2-. The defect sites generated via this activation act as new strong basic sites within the catalyst structure. A fluorescence microscopic visualization of the activity convincingly proves that it is exclusively associated with the hexagonal crystals, and that reaction proceeds inside the crystal's interior. Theoretical analysis of the Ba-material shows that the basicity of the proposed Ba2+-O2--Ba2+motifs is close to that of the edge sites in BaO. This journal is
Rapid synthesis of substituted pyrrolines and pyrrolidines by nucleophilic ring closure at activated oximes
Chandan, Nandkishor,Thompson, Amber L.,Moloney, Mark G.
supporting information, p. 7863 - 7868 (2013/07/05)
Substituted pyrrolines are available by ring closure initiated by direct nucleophilic attack of stabilized enolates at the nitrogen of oximes activated with a leaving group, in a process which effectively out-competes the more usual Beckmann rearrangement. Subsequent reduction provides diastereoselective access to the corresponding pyrrolidines. This provides a rapid route to saturated heterocyclic systems from readily available precursors.
An efficient synthesis of 3-alkyl-1,5,3-dioxazepanes and their use as electrophiles in double-Mannich reactions
Sparrow, Kevin,Barker, David,Brimble, Margaret A.
experimental part, p. 1017 - 1028 (2012/02/13)
An efficient synthesis of 3-alkyl 1,5,3-dioxazepanes was developed for subsequent use in double-Mannich reactions with a variety of carbon-based nucleophiles. It was found that addition of methyltrichlorosilane to the dioxazepane led to a long-lasting rea
N-heterocyclic carbene-catalyzed michael additions of 1,3-dicarbonyl compounds
Boddaert, Thomas,Coquerel, Yoann,Rodriguez, Jean
scheme or table, p. 2266 - 2271 (2011/03/22)
A study of the organocatalytic activity of N-heterocyclic carbenes (NHCs) in the Michael addition of 1,3-dicarbonyl compounds has allowed us to identify 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) as an excellent catalyst for this transformatio
Tin(IV) triflimidate-catalyzed cyclization of epoxy esters to functionalized δ-hydroxy-γ-lactones
Antoniotti, Sylvain,Du?ach, Elisabet
scheme or table, p. 2536 - 2539 (2009/07/26)
In the presence of 5 mol % of tin(IV) triflimidate, a cyclization reaction of epoxyesters to δ-hydroxy-γ-lactones proceeding in 46-98% yields without additives, ligands, or co-catalysts was observed. The cyclization to five-membered rings is greatly favor
Nickel complexes of nio-functionalized n-Heterocyclic carbenes as precatalysts for michael reactions in air at room temperature under the much preferred base-Free conditions
Ray, Sriparna,Shaikh, Mobin M.,Ghosh, Prasenjit
experimental part, p. 1932 - 1941 (2009/10/30)
A series of several new nickel precatalysts supported over N/O-functionalized N-heterocyclic carbenes (NHC) for the Michael reactions of B-dicarbonyl, B-keto ester, B-diester, and a-cyano ester compounds with a,B-unsaturated carbonyl compounds in air at ambient temperature under the much preferred base-free conditions are reported. Specifically, the nickel complexes, [1-(R1-aminocarbonylmethyl)-3-R2-imid-azol-2-ylidene]2Ni [R1 =2-C6H4(OMe); R2 = Me (1b), iPr (2b), CH2Ph (3b) and R1 = 2-CH2C4H3O; R2 =Me (4b), CH2Ph (5b)] carried out the highly convenient base-free Michael addition of the activated C-H compounds across a,B-unsaturated car- bonyl compounds in air at room temperature. The complexes 1b-5b were synthesized by the direct reaction of the respective imidazolium chloride salt with NiCl2-6H2Oin CH3CN in the presence of K2CO3 as a base. The exceptional stability of 1b-5b has been attributed to the deeply buried nickel-NHC CT-bonding molecular orbitals as evidenced from the density functional theory (DFT) studies. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009.
Ionic liquid as catalyst and solvent: the remarkable effect of a basic ionic liquid, [bmIm]OH on Michael addition and alkylation of active methylene compounds
Ranu, Brindaban C.,Banerjee, Subhash,Jana, Ranjan
, p. 776 - 782 (2007/10/03)
A basic ionic liquid, 1-methyl-3-butylimidazolium hydroxide, [bmIm]OH, catalyzes the Michael addition of active methylene compounds to conjugated ketones, carboxylic esters and nitriles. It further catalyzes the addition of thiols to α,β-acetylenic ketones and alkylation of 1,3-dicarbonyl and -dicyano compounds. The Michael addition to α,β-unsaturated ketones proceeds in the usual way, giving the monoaddition products, whereas addition to α,β-unsaturated esters and nitriles leads exclusively to the bis-addition products. The α,β-acetylenic ketones undergo double conjugate addition with thiols producing β-keto 1,3-dithio-derivatives. In the alkylation reaction the acyclic 1,3-diketones are monoalkylated, whereas cyclic ketones undergo dialkylation under identical conditions. All these reactions were carried out without any organic solvent. The ionic liquid can also be recycled.
