23010-14-2Relevant articles and documents
Transition-Metal-Free Synthesis of Polyfunctional Triarylmethanes and 1,1-Diarylalkanes by Sequential Cross-Coupling of Benzal Diacetates with Organozinc Reagents
Wei, Baosheng,Ren, Qianyi,Bein, Thomas,Knochel, Paul
, p. 10409 - 10414 (2021/03/26)
A variety of functionalized triarylmethane and 1,1-diarylalkane derivatives were prepared via a transition-metal-free, one-pot and two-step procedure, involving the reaction of various benzal diacetates with organozinc reagents. A sequential cross-coupling is enabled by changing the solvent from THF to toluene, and a two-step SN1-type mechanism was proposed and evidenced by experimental studies. The synthetic utility of the method is further demonstrated by the synthesis of several biologically relevant molecules, such as an anti-tuberculosis agent, an anti-breast cancer agent, a precursor of a sphingosine-1-phosphate (S1P) receptor modulator, and a FLAP inhibitor.
Metal-Free Aerobic Oxidative C–O Coupling of C(sp3)–H with Carboxylic Acids Catalyzed by DDQ and tert-Butyl Nitrite
Pan, Decheng,Pan, Zilong,Hu, Zhiming,Li, Meichao,Hu, Xinquan,Jin, Liqun,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu
, p. 5650 - 5655 (2019/08/20)
The formation of the C–O bond is one of the hot topics in the area of C(sp3)–H bond functionalization. A metal-free oxidative cross-coupling between benzylic C(sp3)–H bond and carboxylic acids has been developed. The reactions were performed with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as the catalyst, tert-butyl nitrite (TBN) as the co-catalyst, and molecular oxygen as the terminal oxidant. A variety of diarylmethanes could be successfully coupled with various carboxylic acids to obtain diarylmethanol esters in good to excellent yields. In addition, 2-benzylbenzoic acids could be converted into phthalides in moderate yields through an intramolecular oxidative cyclization.
Cobalt-Catalyzed Decarboxylative Acetoxylation of Amino Acids and Arylacetic Acids
Xu, Kun,Wang, Zhiqiang,Zhang, Jinjin,Yu, Lintao,Tan, Jiajing
supporting information, p. 4476 - 4478 (2015/09/28)
The first cobalt-catalyzed decarboxylative acetoxylation reaction was accomplished. This methodology is applicable to a wide range of amino acids and arylacetic acids.
Kinetic resolution of diarylmethanols using a mutated variant of lipase CALB
Engstr?m, Karin,Vallin, Michaela,Hult, Karl,B?ckvall, Jan-E.
experimental part, p. 7613 - 7618 (2012/09/07)
An enzymatic kinetic resolution of diarylmethanols via acylation has been developed. This was achieved by the use of a mutated variant of CALB that accepts larger substrates compared to the wild type. By the use of diarylmethanols with two differently sized aryl groups, enantioselective transformations were achieved. A larger size-difference led to a higher enantioselectivity. In addition, substrates with electronically different aryl groups, such as phenyl and pyridyl, also gave an enantioselective reaction. The highest E value was observed with a substrate where steric and electronic effects were combined.
DDQ-catalyzed oxidative C-O coupling of sp3 C-H bonds with carboxylic acids
Yi, Hong,Liu, Qiang,Liu, Jie,Zeng, Ziqi,Yang, Yuhong,Lei, Aiwen
, p. 2143 - 2146 (2013/01/15)
Da-ddy, DDQ: By using catalytic amounts of DDQ combined with MnO 2 as oxidant, an efficient oxidative C-O coupling of benzylic sp 3 C-H bonds with carboxylic acids affords a series of carboxylic esters in 70-98 % yields. A wide range
Copper-catalyzed substitution reactions of acylal with organomanganese reagents
Deshmukh, Madhukar B.,Jadhav, Sunil D.,Kadam, Shashikant V.
, p. 989 - 994 (2008/09/18)
A mild method for the copper-catalyzed substitution of aldehyde acylals with organomanganese reagents is reported. This operationally simple C-C bond-forming protocol uses different Cu(I) catalysts. Acylal from trans-cinnamaldehyde furnishes conjugated addition product when reacted with alkyl and aryl organomanganese reagents in presence of 10 mol % of Cu(NCMe) 2 (PPh3)2[BF4] and 2 equivalent of Me3Si-C1 as an accelerator. This reagent can be efficiently used in the substitution of one acetate group of aromatic acylal to form esters in high yield.
Trans-esterification in dry media using ferric perchlorate adsorbed on silica gel
Parmar, Anupama,Goyal, Rita,Kumar, Baldev,Kumar, Harish
, p. 139 - 143 (2007/10/03)
Adsorption of Fe(ClO4)3(H2O)6 onto chromatographic grade silica gel in the presence of ethyl acetate (to be used for trans-esterification) produces a supported reagent, Fe(ClO4)3(EtOAc)6/SiO2. This reagent, has been found effective for the rapid and high yield of esters via trans- esterification on grinding in the presence of alcohols/carboxylic acids using pestle and mortar in the solid state.
Iron (III) perchlorate: A reagent for trans-esterification
Kumar, Baldev,Kumar, Harish,Parmar, Anupama
, p. 292 - 293 (2007/10/02)
Iron (III) perchlorate has successfully been used for the trans-esterification of ethyl acetate with alcohols and acids.
A novel synthesis of esters via substitution of the benzotriazolyl group in 1-(benzotriazol-1-yl)alkyl esters with organozinc reagents
Katritzky,Rachwal,Rachwal
, p. 69 - 73 (2007/10/02)
Aldehydes are converted by thionyl chloride and benzotriazole into 1-(1-chloroalyl)benzotriazoles which react with sodium carboxylates to give 1-(benzotriazol-1-yl)alkyl esters. 3. In the alternative route, 3 are prepared by substitution of one of the acetoxy groups in acylals with benzotriazole. The benzotriazolyl moiety in 3 is substituted by an alkyl, an aryl or an alkynyl group upon treatment with an organic reagent in a new versatile synthesis of esters 4.
