86668-30-6Relevant articles and documents
Direct deoxygenation of active allylic alcohols via metal-free catalysis
Han, Feng,Ji, Na,Liu, Qiaowen,Miao, Chengxia,Zhang, Tong,Zhuang, Hongfeng
, p. 1680 - 1689 (2022/03/02)
Direct metal-free deoxygenation of highly active allylic alcohols catalyzed by a Br?nsted acid was achieved, which avoids tedious reaction steps and eliminates metal contamination. By examining a series of Br?nsted acids, alcohols, reaction temperatures and so on, up to 94% yield was obtained with 10 mol% TsOH·H2O as the catalyst and 2 equiv. of p-methylbenzyl alcohol as the reductant at 80 °C for 2 h. The system was mainly suitable for aromatic allylic alcohols, and the yield was excellent as determined via gram-scale synthesis. The main product was double bond near the side of a more electron-rich aryl group when allylic alcohols featuring different substituents at the 1 and 3 positions were used as the substrates. Deuterium-labelled experiments clearly demonstrated that the hydrogen source was the methylene of p-methylbenzyl alcohol and other control experiments indicated the existence of two ether intermediates. Interestingly, in situ hydrogen transfer of allylic benzyl ether is a key process, but kinetic isotopic effect studies (kH/kD = 1.28) showed that the C-H bond cleavage was not the rate-determining step. A possible mechanism involving carbocations, ether intermediates and hydrogen transfer is proposed.
A photocatalyst-free photo-induced denitroalkylation of β-nitrostyrenes with 4-alkyl substituted Hantzsch esters at room temperature
Duan, Chunying,Hao, Xinyu,Jin, Kun,Li, Yaming,Wang, Jiaao,Zhang, Rong,Zhang, Siyu
supporting information, (2020/02/18)
A photocatalyst-free stereoselectively photo-induced strategy for the denitroalkylation of β-nitrostyrenes using 4-alkyl substituted Hantzsch esters as the alkyl source under xenon lamp irradiation is developed. The reaction proceeds at room temperature and affords the corresponding products in moderate to excellent yields. The oxidant di-t-butyl peroxide serves as an efficient radical initiator under irradiation of a Xenon lamp, initiating alkyl radicals from the 4-alkyl substituted Hantzsch esters.
[Pd]-Catalyzed Intermolecular Coupling and Acid Mediated Intramolecular Cyclodehydration: One-Pot Synthesis of Indenes
Niharika, Pedireddi,Satyanarayana, Gedu
, p. 971 - 979 (2018/02/22)
An efficient one-pot synthesis of indenes from simple starting materials is presented. This process involves a dual C–C bond formation through an intermolecular Heck coupling reaction followed by acid-mediated intramolecular cyclodehydration. The strategy
Synthesis of (E)-prop-1-ene-1,3-diyldibenzene derivatives via direct decarboxylative coupling of α,β-unsaturated carboxylic acids with benzyl boronic acid pinacol ester
Zhu, Mingxiang,Qiu, Zhenjiang,Zhang, Yun,Du, Hongli,Li, Jingya,Zou, Dapeng,Wu, Yangjie,Wu, Yusheng
, p. 2255 - 2257 (2018/03/26)
The first copper-catalyzed cross-coupling reaction between benzyl boronic acid pinacol ester and α,β-unsaturated carboxylic acids was described. The ready availability of the starting materials and excellent E selectivity make this protocol a safe and operationally convenient strategy for the efficient synthesis of (E)-prop-1-ene-1,3-diyldibenzene derivatives.
Photochemical Heck benzylation of styrenes catalyzed by Na[FeCp(CO)2]
Waldhart, Greyson W.,Mankad, Neal P.
supporting information, p. 171 - 174 (2015/03/05)
Iron-catalyzed Heck coupling of benzyl chlorides and styrenes proceeds under photochemical conditions using the well-known anionic complex, [FeCp(CO)2]- (Fp-), as a catalyst. The reaction likely proceeds through the established SN2 mechanism for Fp- alkylation, followed by styrene migratory insertion and β-hydride elimination steps that are enabled by photochemical CO dissociation.
Direct olefination of benzaldehydes into 1,3-diarylpropenes via a copper-catalyzed heterodomino Knoevenagel-decarboxylation-Csp3-H activation sequence
Zhao, Yaping,Sun, Lu,Zeng, Tieqiang,Wang, Jiayi,Peng, Yanqing,Song, Gonghua
, p. 3493 - 3498 (2014/05/20)
Copper-catalyzed direct olefination of benzaldehydes into 1,3-diarylpropenes by a novel domino Knoevenagel-decarboxylation-Csp 3-H activation sequence is reported. This method provides a concise and effective route toward the synthesis of unsymmetrical 1,3-diarylpropene derivatives. the Partner Organisations 2014.
Iron-catalyzed allylic arylation of olefins via C(sp3)-H activation under mild conditions
Sekine, Masaki,Ilies, Laurean,Nakamura, Eiichi
supporting information, p. 714 - 717 (2013/04/10)
An aryl Grignard reagent in the presence of mesityl iodide converts an allylic C-H bond of a cycloalkene or an allylbenzene derivative into a C-C bond in the presence of a catalytic amount of Fe(acac)3 and a diphosphine ligand at 0 C. The stereo- and regioselectivity of the reaction, together with deuterium labeling experiments, suggest that C-H bond activation is the slow step in the catalytic cycle preceding the formation of an allyliron intermediate.
Rapid selective defunctionalization of the carbonyl group of α,β-unsaturated ketones with trialkoxylsilane/ZnX2
Li, Jiayun,Peng, Jiajian,Bai, Ying,Chen, Lingzhen,Lai, Guoqiao
scheme or table, p. 1621 - 1625 (2011/10/04)
Reduction of the carbonyl group of ketones to a methylene unit is widely applied in organic syntheses. In this article, we report that trialkoxylsilane/Zn-based catalyst systems may be applied in the reduction of the carbonyl groups of α,β-unsaturated ketones to methylene units under very mild conditions. In comparison with other Zn-based catalysts, excellent rates and high conversions of,-unsaturated ketones to methylene units are obtained using trialkoxylsilane/ZnI2 or ZnCl2. And the same time, the hydrosilylation reaction product could only be detected when using CuI, CuCl, or FeCl3. No reaction could be conducted by using trialkoxylsilane/CoCl2 or NiCl2, in comparison with Zn-based catalysts. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. Copyright Taylor &Francis Group, LLC.
Operationally simple and highly (E)-styrenyl-selective heck reactions of electronically nonbiased olefins
Werner, Erik W.,Sigman, Matthew S.
supporting information; experimental part, p. 9692 - 9695 (2011/08/06)
Simple, mild, and efficient conditions are reported for a Pd 0-catalyzed Heck reaction that delivers high yields and selectivity for (E)-styrenyl products using electronically nonbiased olefin substrates bearing a range of useful functionality. Preliminary mechanistic studies demonstrate that the σ-donating DMA solvent is crucial for high selectivity. Further studies suggest that the catalyst distinguishes between β-hydrogens on the basis of their relative hydridic character, in contrast to previously reported PdII-catalyzed oxidative reaction conditions.
Palladium-catalyzed cross-couplings of allylic carbonates with triarylbismuths as multi-coupling atom-efficient organometallic nucleophiles
Rao, Maddali L.N.,Banerjee, Debasis,Giri, Somnath
experimental part, p. 1518 - 1525 (2010/08/03)
Allylic carbonates were efficiently cross-coupled with triarylbismuths under palladium catalysis. Using the optimized protocol, arylations of various allylic carbonates were carried out with triarylbismuths to afford high yields of 1,3-disubstituted prope
