133-13-1Relevant academic research and scientific papers
Synthesis of Cyclopentenones through Rhodium-Catalyzed C-H Annulation of Acrylic Acids with Formaldehyde and Malonates
Yu, Shuling,Hong, Chao,Liu, Zhanxiang,Zhang, Yuhong
supporting information, p. 5054 - 5059 (2021/07/20)
An efficient rhodium-catalyzed protocol for the synthesis of cyclopentenones based on a three-component reaction of acrylic acids, formaldehyde, and malonates via vinylic C-H activation is reported. Exploratory studies showed that 5-alkylation of as-prepared cyclopentenones could be realized smoothly by the treatment of a variety of alkyl halides with a Na2CO3/MeOH solution. Excess formaldehyde and malonate led to a multicomponent reaction that afforded the multisubstituted cyclopentenones through a Michael addition.
Rhodium Porphyrin Catalyzed Regioselective Transfer Hydrogenolysis of C-C σ-Bonds in Cyclopropanes with iPrOH
Chen, Chen,Feng, Shiyu,Chan, Kin Shing
, p. 2582 - 2589 (2019/07/02)
A new rhodium porphyrin catalyzed regioselective transfer hydrogenolysis of both activated and unactivated cyclopropanes employing iPrOH as the hydrogen source was discovered. The reaction mechanism for the C-C σ-bond activation of cyclopropanes was identified through an initial radical substitution with rhodium(II) metalloporphyrin radical to give a rhodium porphyrin alkyl, followed by hydrogenolysis with iPrOH to give the corresponding acyclic alkanes and regenerate rhodium(II) metalloporphyrin radical.
Nano-K2CO3: Preparation, characterization and evaluation of reactive activities
Li, Jun-Zhang,Fan, Shi-Ming,Sun, Xuan-Fei,Liu, Shouxin
, p. 1865 - 1869 (2016/01/20)
A novel base, nano-K2CO3, was easily prepared by ultrafine wet milling. The surface properties and the reactive activities of nano-K2CO3 were characterized. It was found that such a base showed higher basicity than normal K2CO3 and could replace sodium (or potassium) alkoxide to carry out monoalkylation and oximation of active methylene compounds. The nano-K2CO3 could be regenarated and reused 10 times without loss of its reactive activity.
Bifunctional Iminophosphorane Catalyzed Enantioselective Sulfa-Michael Addition to Unactivated α-Substituted Acrylate Esters
Farley, Alistair J. M.,Sandford, Christopher,Dixon, Darren J.
supporting information, p. 15992 - 15995 (2016/01/15)
The highly enantioselective sulfa-Michael addition of alkyl thiols to unactivated α-substituted acrylate esters catalyzed by a bifunctional iminophosphorane organocatalyst under mild conditions is described. The strong Br?nsted basicity of the iminophosphorane moiety of the catalyst provides the necessary activation of the alkyl thiol pro-nucleophile, while the two tert-leucine residues flanking a central thiourea hydrogen-bond donor facilitate high enantiofacial selectivity in the protonation of the transient enolate intermediate. The reaction is broad in scope with respect to the alkyl thiol, the ester moiety, and the α-substituent of the α,β-unsaturated ester, affords sulfa-Michael adducts in excellent yields (up to >99%) and enantioselectivities (up to 96% ee), and is amenable to decagram scale-up using catalyst loadings as low as 0.05 mol %.
Copper(II) triflate catalyzed amination and aziridination of 2-Alkyl substituted 1,3-dicarbonyl compounds
Ton, Thi My Uyen,Tejo, Ciputra,Tiong, Diane Ling Ying,Chan, Philip Wai Hong
experimental part, p. 7344 - 7350 (2012/06/16)
A method to prepare α-acyl-β-amino acid and 2,2-diacyl aziridine derivatives efficiently from Cu(OTf)2 + 1,10-phenanthroline (1,10-phen)-catalyzed amination and aziridination of 2-alkyl substituted 1,3-dicarbonyl compounds with PhI=NTs is described. By taking advantage of the orthogonal modes of reactivity of the substrate through slight modification of the reaction conditions, a divergence in product selectivity was observed. In the presence of 1.2 equiv of the iminoiodane, amination of the allylic C-H bond of the enolic form of the substrate, formed in situ through coordination to the Lewis acidic metal catalyst, was found to selectively occur and give the β-aminated adduct. On the other hand, increasing the amount of the nitrogen source from 1.2 to 2-3 equiv was discovered to result in preferential formal aziridination of the C-C bond of the 2-alkyl substituent of the starting material and formation of the aziridine product.
Palladium-catalyzed cycloisomerizations of (Z)-1-iodo-1,6-dienes: Iodine atom transfer and mechanistic insight to alkyl iodide reductive elimination
Liu, Hui,Li, Chaolong,Qiu, Dong,Tong, Xiaofeng
supporting information; experimental part, p. 6187 - 6193 (2011/06/22)
A palladium-catalyzed iodine atom transfer cycloisomerization of (Z)-1-iodo-1,6-diene has been developed, which provides a facile method to construct six-memebered heterocycles bearing an alkyl iodide group. The ligand screening shows that both the type and the quantity of ligand impose significant influences on this transformation, and the combination of 30 mol % 1,1′-bis(diphenylphosphino)ferrocene (DPPF) and 10 mol % Pd(OAc) 2 is the optimal choice. The catalytic cycle, consisting of oxidative addition of Pd(0) to vinyl iodide, intramolecular alkene insertion, and alkyl iodide reductive elimination, has been proposed and eventually supported by convincing evidence from a series of control experiments. More importantly, these control experiments disclose some features of the event of alkyl iodide reductive elimination: (1) this reductive elimination is proved to be a stereospecific process; and (2) both alkyl iodide oxidative addition and reductive elimination are not effected by a TEMPO additive. Besides its ability to undergo oxidative addition, the catalyst (palladium + DPPF) could also promote a radical transfer process. The findings described in this paper will be helpful for further development of the metal-catalyzed formation of a carbon-halide bond.
Pheromones and analogs from Neozeleboria wasps and the orchids that seduce them: a versatile synthesis of 2,5-dialkylated 1,3-cyclohexanediones
Poldy, Jacqueline,Peakall, Rod,Barrow, Russell A.
, p. 2446 - 2449 (2008/09/20)
Chiloglottone, a wasp pheromone and attractant of sexually deceptive Chiloglottis orchids, and several structural analogs were synthesized. The synthetic approach is facile, high yielding and versatile, enabling rapid divergence to generate dialkylated analogs of chiloglottone. The key transformation was an organocadmium-mediated desymmetrization of glutaric anhydride derivatives. This library of synthetic 2,5-dialkylated 1,3-cyclohexanediones may assist in future identification of natural products in further species.
Toward a total synthesis of the novel polyketide natural product spiculoic acid A
Mehta, Goverdhan,Kundu, Uday Kumar
, p. 5569 - 5572 (2007/10/03)
(Chemical Equation Presented) An enantioselective approach toward the recently isolated marine natural product, spiculoic acid A, conceptualized along the proposed biogenetic hypothesis, involving an intramolecular Diels-Alder reaction as the pivotal step
Pyran-2-ones and 5,6-dihydropyran-2-ones useful for treating hyperplasia and other diseases
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Page 36, 158, (2010/02/05)
Certain 2H-pyran-2-ones are useful for treating benign prostatic hypertrophy or hyperplasia, prostatic cancer, alopecia, hirsutism, acne vulgaris and seborrhea.
Applications of diethoxymethane as a versatile process solvent and unique reagent in organic synthesis
Boaz, Neil W.,Venepalli, Bhaskar
, p. 127 - 131 (2013/09/07)
Diethoxymethane (DEM) has recently become available in commercial quantities. It has unique properties and is useful in a variety of applications in organic synthesis. It is low boiling (88 °C), azeotropes with water, and has a very low affinity for water. It is stable under basic conditions and as manufactured does not require drying for use as a solvent, even for organometallic reactions. DEM is useful as a process solvent especially for sodium hydride reactions, organolithium chemistry, copper-catalyzed conjugate additions, and phase-transfer reactions. As such, DEM is a potential replacement for tetrahydrofuran (THF), dichloromethane (CH2Cl2), glyme (1,2-dimethoxyethane), and methylal (1,1-dimethoxymethane). DEM is also useful as an ethoxymethylating agent, a formaldehyde equivalent, and a carbonylation substrate. Due to these unique properties and applications, DEM has exciting potential for widespread use both as a reagent and especially as a preferred solvent.
