37592-19-1Relevant academic research and scientific papers
Nickel-catalyzed deallylation of aryl allyl ethers with hydrosilanes
Ding, Guangni,Fan, Sijie,Wang, Jingyang,Wang, Yu,Wu, Xiaoyu,Xie, Xiaomin,Yang, Liqun,Zhang, Zhaoguo
supporting information, (2021/09/28)
An efficient and mild catalytic deallylation method of aryl allyl ethers is developed, with commercially available Ni(COD)2 as catalyst precursor, simple substituted bipyridine as ligand and air-stable hydrosilanes. The process is compatible with a variety of functional groups and the desired phenol products can be obtained with excellent yields and selectivity. Besides, by detection or isolation of key intermediates, mechanism studies confirm that the deallylation undergoes η3-allylnickel intermediate pathway.
Nickel Hydride Catalyzed Cleavage of Allyl Ethers Induced by Isomerization
Kathe, Prasad M.,Berkefeld, Andreas,Fleischer, Ivana
supporting information, p. 1629 - 1632 (2021/02/09)
This report discloses the deallylation of O - and N -allyl functional groups by using a combination of a Ni-H precatalyst and excess Bronsted acid. Key steps are the isomerization of the O - or N -allyl group through Ni-catalyzed double-bond migration followed by Bronsted acid induced O/N-C bond hydrolysis. A variety of functional groups are tolerated in this protocol, highlighting its synthetic value.
Nano-dispersed platinum(0) in organically modified silicate matrices as sustainable catalysts for a regioselective hydrosilylation of alkenes and alkynes
Duke, Brett J.,Akeroyd, Evan N.,Bhatt, Shreeja V.,Onyeagusi, Chibueze I.,Bhatt, Shreya V.,Adolph, Brandy R.,Fotie, Jean
, p. 11782 - 11795 (2018/07/25)
Nano-dispersed platinum(0) particles stabilized in a range of organically modified silicate (ORMOSIL) matrices are investigated as sustainable catalysts for the hydrosilylation of alkenes and alkynes. In this study, five different siloxane matrices including triethoxysilane (HTEOS), methyltriethoxysilane (MTES), ethyltriethoxysilane (ETES), triethoxyvinylsilane (TEVS) and propyltriethoxysilane (PTES) are investigated, and the distribution of the metal particles in these materials analyzed by transition electron microscopy (TEM). The particles appeared to be generally of a small size, with a diameter of ca. 2-5 nm in each of these catalysts, however the distribution is not equally uniform from one matrix to the other. HTEOS, MTES and ETES that respectively carry a hydrogen, a methyl and an ethyl group on the triethoxysilane moiety, displayed a more uniform distribution, while particles appeared to be more scattered in the remaining matrices. Catalysts with a uniform particles distribution produced higher and consistent yields, while those with poor particles distribution produced lower and almost random yields, suggesting that the uniformity in particle distribution, and by extension the nature of the siloxane matrix, are important for the catalytic properties of these materials. The scope of the reaction was broadened to a range of olefins, with a goal of investigating the tolerability of the reaction toward a number of reactive functional groups, resulting in the preparation of 28 compounds. This catalytic system also enabled the hydrosilylation of a limited number of alkynes under the optimized reaction conditions.
Direct C-H Cyanation of Arenes via Organic Photoredox Catalysis
McManus, Joshua B.,Nicewicz, David A.
supporting information, p. 2880 - 2883 (2017/03/11)
Methods for the direct C-H functionalization of aromatic compounds are in demand for a variety of applications, including the synthesis of agrochemicals, pharmaceuticals, and materials. Herein, we disclose the construction of aromatic nitriles via direct C-H functionalization using an acridinium photoredox catalyst and trimethylsilyl cyanide under an aerobic atmosphere. The reaction proceeds at room temperature under mild conditions and has proven to be compatible with a variety of electron-donating and -withdrawing groups, halogens, and nitrogen- and oxygen-containing heterocycles, as well as aromatic-containing pharmaceutical agents.
A mild copper catalyzed method for the selective deprotection of aryl allyl ethers
Hemming, David S.,Talbot, Eric P.,Steel, Patrick G.
supporting information, p. 17 - 20 (2016/12/23)
Copper boryl reagents enable the selective cleavage of aryl allyl ethers to the corresponding phenols in good to moderate yields.
Regioselective Alkoxycarbonylation of Allyl Phenyl Ethers Catalyzed by Pd/dppb under Syngas Conditions
Amézquita-Valencia, Manuel,Alper, Howard
, p. 3860 - 3867 (2016/05/24)
A simple and regioselective synthesis of phenoxy esters and phenylthio esters is reported. The products are obtained by selective alkoxycarbonylation catalyzed by Pd2(dba)3, 1,4-bis(diphenylphisphino)butane (dppb), and syngas (CO/H2) in chloroform/alcohol. This methodology affords bifunctional products in good yield with excellent n-selectivity and without the need to use additives.
Radical Hydrodeiodination of Aryl, Alkenyl, Alkynyl, and Alkyl Iodides with an Alcoholate as Organic Chain Reductant through Electron Catalysis
Dewanji, Abhishek,Mück-Lichtenfeld, Christian,Studer, Armido
, p. 6749 - 6752 (2016/06/09)
A simple and efficient method for radical hydrodeiodination is reported. The novel approach uses electron catalysis. In situ generated Na-alcoholates are introduced as radical chain reducing reagents and reactions work with O2as cheap initiator. Hydrodeiodination works on aryl, alkenyl, alkynyl iodides and a tert-alkyl iodide also gets reduced applying the method. Albeit less general, the method is also applicable to the reduction of aryl bromides. The novel reagent is successfully used to conduct typical reductive radical cyclization reactions and mechanistic studies are reported.
Catalytic enantioselective cyclization/cross-coupling with alkyl electrophiles
Cong, Huan,Fu, Gregory C.
supporting information, p. 3788 - 3791 (2014/04/03)
As part of our ongoing effort to expand the scope of cross-coupling reactions of alkyl electrophiles, we have pursued a strategy wherein the nucleophilic coupling partner includes a pendant olefin; after transmetalation by such a substrate, if β-migratory insertion proceeds faster than direct cross-coupling, an additional carbon-carbon bond and stereocenter can be formed. With the aid of a nickel/diamine catalyst (both components are commercially available), we have established the viability of this approach for the catalytic asymmetric synthesis of 2,3-dihydrobenzofurans and indanes. Furthermore, we have applied this new method to the construction of the dihydrobenzofuran core of fasiglifam, as well as to a cross-coupling with a racemic alkyl electrophile; in the latter process, the chiral catalyst controls two stereocenters, one that is newly generated in a β-migratory insertion and one that begins as a mixture of enantiomers.
NiCl2·6H2O/NaBH4 in methanol: A mild and efficient strategy for chemoselective deallylation/debenzylation of aryl ethers
Chouhan, Mangilal,Kumar, Kapil,Sharma, Ratnesh,Grover, Vikas,Nair, Vipin A.
supporting information, p. 4540 - 4543 (2013/08/23)
Deprotection of allyl/benzyl aryl ethers was achieved chemoselectively. The mild and inexpensive reagent combination of NiCl2·6H 2O/NaBH4 in methanol afforded the products in high yields, within a reaction time of 5-10 min.
Enantioselective synthesis of benzofurans and benzoxazines via an olefin cross-metathesis-intramolecular oxo-Michael reaction
Zhang, Jun-Wei,Cai, Quan,Gu, Qing,Shi, Xiao-Xin,You, Shu-Li
supporting information, p. 7750 - 7752 (2013/09/02)
Chiral phosphoric acid and Hoveyda-Grubbs II were found to catalyze an olefin cross-metathesis-intramolecular oxo-Michael cascade reaction of the ortho-allylphenols and enones to provide a variety of benzofuran and benzoxazine derivatives in moderate to good yields and enantioselectivity.
