4799-69-3Relevant articles and documents
A Chiral Copper Catalyzed Site-Selective O-Alkylation of Carbohydrates
Ren, Bo,Wang, Jiaxi,Zhang, Mengyao,Chen, Yue,Zhao, Wei
supporting information, p. 665 - 670 (2021/12/02)
Highly regioselective alkylation of sugar hydroxyl groups has always been an important challenge in carbohydrate chemistry, especially for the selective alkylation of trans diols, there is no direct and efficient catalytic method so far. A chiral copper c
Stereoselective synthesis of resorcylic acid lactone Cochliomycin B
Nagalatha,Siva Ganesh,Venkat Narsaiah
, (2021/09/22)
The total synthesis of 14-membered resorcylic acid lactone, Cochliomycin B has prescribed, in a convergent manner, from readily available starting materials, D-galactose, L-aspartic acid and ethyl acetoacetate. The key reactions involved in the synthesis are Julia-Kocienski olefination, E-selective Horner-Wadsworth-Emmons olefination and intramolecular lactonization.
Benzoxaborole Catalyst for Site-Selective Modification of Polyols
Kusano, Shuhei,Miyamoto, Shoto,Matsuoka, Aki,Yamada, Yuji,Ishikawa, Ryuta,Hayashida, Osamu
supporting information, p. 1598 - 1602 (2020/02/11)
The site-selective modification of polyols bearing several hydroxyl groups without the use of protecting groups remains a significant challenge in synthetic chemistry. To address this problem, novel benzoxaborole derivatives were designed as efficient catalysts for the highly site-selective and protecting-group-free modification of polyols. To identify the effective substituent groups enhancing the catalytic activity and selectivity, a series of benzoxaborole catalysts 1a–k were synthesized. In-depth analysis for the substituent effect revealed that 1i–k, bearing multiple electron-withdrawing fluoro- and trifluoromethyl groups, exhibited the greatest catalytic activity and selectivity. Moreover, 1i-catalyzed benzoylation, tosylation, benzylation, and glycosylation of various cis-1,2-diol derivatives proceeded with good yield and site-selective manner.
Preparation method of alkyl nitrile compound
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Paragraph 0159-0160; 0162, (2020/05/14)
The invention discloses a preparation method of an alkyl nitrile compound shown as formula I. The preparation method comprises the following step: in a solvent, in the presence of an additive and a catalyst, Zn (CN) 2 and an alkyl halide shown as formula II are subjected to a coupling reaction as shown in the specification to obtain the alkyl nitrile compound as shown in the formula I, wherein theadditive comprises an alkali, the catalyst comprises a nickel compound and a phosphine ligand; the nickel compound is one or more of zero-valent nickel, monovalent nickel salt and divalent nickel salt; when the nickel compound contains zero-valent nickel or divalent nickel salt, the catalyst further comprises a reducing agent. According to the preparation method disclosed by the invention, cyanation of an alkyl halide can be simply, conveniently and efficiently realized by using a cheap catalytic system, and the preparation method also has good functional group compatibility and substrate universality.
Stereoselective total synthesis of C2-symmetric natural products pyrenophorol and its derivatives
Narala, Siva Ganesh,Nagalatha,Venkat Narsaiah
supporting information, p. 2173 - 2178 (2019/03/11)
A stereoselective total synthesis of 16-membered C2-symmetric macrodiolide Pyrenophorol, Tetrahydropyrenophorol and 4,4-diacetylpyrenophorol have been accomplished. The synthesis started from commercially available L-Aspartic acid and the key reactions involved are regioselective epoxide opening, CBS reduction, Pinnick oxidation and Mitsunobu dilactonization.
Regio/site-selective alkylation of substrates containing a: Cis -, 1,2- or 1,3-diol with ferric chloride and dipivaloylmethane as the catalytic system
Lv, Jian,Liu, Yu,Zhu, Jia-Jia,Zou, Dapeng,Dong, Hai
supporting information, p. 1139 - 1144 (2020/03/11)
In this study, we reported the regio/site-selective alkylation of substrates containing a cis-, 1,2- or 1,3-diol with FeCl3 as a key catalyst. A catalytic system consisting of FeCl3 (0.01-0.1 equiv.) and dipivaloylmethane (FeCl3/dipivaloylmethane = 1/2) was used to catalyze the alkylation in the presence of a base. The produced selectivities and isolated yields were similar to those obtained by methods using the same amount of FeL3 (L = acylacetone ligand) as the catalyst in most cases. The previously reported FeL3 catalysts for alkylation are not commercially available and have to be synthesized prior to use. In contrast, FeCl3 and dipivaloylmethane (Hdipm) are very common and inexpensive nontoxic reagents in the lab, thereby making the method much greener and easier to handle. Mechanism studies confirmed for the first time that FeCl3 initially reacts with two equivalents of Hdipm to form [Fe(dipm)3] in the presence of a base in acetonitrile, followed by the formation of a five or six-membered ring intermediate between [Fe(dipm)3] and two hydroxyl groups of the substrate. A subsequent reaction between the cyclic intermediate and the alkylating agent results in selective alkylation of the substrate.
Dehalogenative Deuteration of Unactivated Alkyl Halides Using D2O as the Deuterium Source
Xia, Aiyou,Xie, Xin,Hu, Xiaoping,Xu, Wei,Liu, Yuanhong
, p. 13841 - 13857 (2019/10/17)
The general dehalogenation of alkyl halides with zinc using D2O or H2O as a deuterium or hydrogen donor has been developed. The method provides an efficient and economic protocol for deuterium-labeled derivatives with a wide substrate scope under mild reaction conditions. Mechanistic studies indicated that a radical process is involved for the formation of organozinc intermediates. The facile hydrolysis of the organozinc intermediates provides the driving force for this transformation.
Selective alkyl ether cleavage by cationic bis(phosphine)iridium complexes
Jones, Caleb A. H.,Schley, Nathan D.
supporting information, p. 1744 - 1748 (2019/02/20)
Catalysts capable of heterolytic silane activation have been successfully applied to the conversion of alkyl ethers to silyl ethers via C-O bond cleavage. The previously-reported cationic pincer-supported iridium complex for this transformation suffers fr
Nickel-Catalyzed Cyanation of Unactivated Alkyl Chlorides or Bromides with Zn(CN)2
Xia, Aiyou,Xie, Xin,Chen, Haoyi,Zhao, Jidong,Zhang, Chunli,Liu, Yuanhong
supporting information, p. 7735 - 7739 (2019/01/03)
A nickel-catalyzed cyanation of unactivated secondary alkyl chlorides or bromides using less toxic Zn(CN)2 as the cyanide source has been developed. The reaction features the use of air-stable and inexpensive NiCl2·6H2O or Ni(acac)2 as the precatalysts and offers an efficient synthesis of a broad range of alkyl nitriles. Cyanation of primary alkyl chlorides or bromides was also achieved by reaction with Zn(CN)2 in the presence of n-Bu4NCl without the need of nickel catalyst.
A formal anti-Markovnikov hydroalkoxylation of allylic alcohols with a ruthenium catalyst
Nakamura, Yushi,Ohta, Tetsuo,Oe, Yohei
supporting information, p. 288 - 291 (2018/02/14)
Hydroalkoxylation of C-C double bonds was achieved through the use of a ruthenium catalyst. The reaction of allylic alcohols with nucleophilic alcohols was carried out in the presence of a ruthenium catalyst prepared by RuClH(CO)(PPh3)3 and 2,6-bis(n-butyliminomethyl)-4-(piperidin-1-yl)pyridine under mild reaction conditions to afford the corresponding γ-alkoxypropanols in good yield.
