64698-32-4Relevant academic research and scientific papers
Triarylborane-Catalyzed Alkenylation Reactions of Aryl Esters with Diazo Compounds
Ariafard, Alireza,Babaahmadi, Rasool,Dasgupta, Ayan,Gierlichs, Lukas,Melen, Rebecca L.,Stefkova, Katarína
, p. 15492 - 15496 (2020)
Herein we report a facile, mild reaction protocol to form carbon–carbon bonds in the absence of transition metal catalysts. We demonstrate the metal-free alkenylation reactions of aryl esters with α-diazoesters to give highly functionalized enyne products. Catalytic amounts of tris(pentafluorophenyl)borane (10–20 mol %) are employed to afford the C=C coupled products (31 examples) in good to excellent yields (36–87 %). DFT studies were used to elucidate the mechanism for this alkenylation reaction.
149. Carbenoid reactions of dimethyl diazomalonate with aromatic thioketones and 1,3-thiazole-5(4H)-thiones
Mloston, Grzegorz,Heimgartner, Heinz
, p. 1785 - 1792 (1996)
Dimethyl diazomalonate (4) and thiobenzophenone (2a) do not react in toluene even after warming to 50°. After addition of catalytic amounts of Rh2(OAc)4, a smooth reaction under N2 evolution afforded a mixture of thiiranedicarboxylate 5 and (diphenylmethylidene)malonate 6 (Scheme 2). A reaction mechanism via an intermediate 'thiocarbonyl ylide' 7, formed by the addition of the carbenoid species 8 to the S-atom of 2a, is plausible. Similar reactions were carried out with 9H-xanthene-9-thione (2b), 9H-thioxanthene-9-thione (2c, Scheme 4), and 1,3-thiazole-5(4H)-thione 18 (Scheme 6). In the cases of 2b and 2c, spirocyclic 1,3-dithiolanetetracarboxylates 14a and 14b, respectively, were obtained as the third product. Reaction mechanisms for their formation are proposed in Scheme 5 : S-transfer from intermediate thiirane 12 to the carbenoid species yielded thiosomalonate 15 which underwent a 1,3-dipolar cycloaddition with 'thiocarbonyl ylide' 16. An alternative is the formation of 'thiocarbonyl ylide' 17 via carbene addition to 15, followed by 1,3-dipolar cycloaddition with 2b and 2c, respectively.
All-Carbon Tetrasubstituted Olefins Synthesis from Diazo Compounds and Iodonium Ylides under Blue LED Irradiation
Zhao, Yan-Rui,Li, Lei,Xu, Guo-Yong,Xuan, Jun
, p. 506 - 511 (2021/12/08)
A route for the construction of all-carbon tetra-substituted olefins through visible-light promoted coupling of diazo compounds with iodonium ylides was developed. A wide range of all-carbon tetra-substituted olefins was obtained in moderate to good yields. The synthetic values of the current method were further approved by the synthesis of natural isolates modified alkenes and the successful transformation of final olefins into important heterocycles. (Figure presented.).
A Unified Catalytic Asymmetric (4+1) and (5+1) Annulation Strategy to Access Chiral Spirooxindole-Fused Oxacycles
Gao, Min,Gong, Xiangnan,Hu, Lin,Luo, Yanshu,Xia, Yuanzhi,Xu, Qianlan,Zhao, Yukun
supporting information, p. 19813 - 19820 (2021/08/03)
A unified catalytic asymmetric (N+1) (N=4, 5) annulation reaction of oxindoles with bifunctional peroxides has been achieved in the presence of a chiral phase-transfer catalyst (PTC). This general strategy utilizes peroxides as unique bielectrophilic four- or five-atom synthons to participate in the C?C and the subsequent umpolung C?O bond-forming reactions with one-carbon unit nucleophiles, thus providing a distinct method to access the valuable chiral spirooxindole-tetrahydrofurans and -tetrahydropyrans with good yields and high enantioselectivities under mild conditions. DFT calculations were performed to rationalize the origin of high enantioselectivity. The gram-scale syntheses and synthetic utility of the resultant products were also demonstrated.
Fe(II)-Catalyzed alkenylation of benzylic C-H bonds with diazo compounds
Shi, Jiang-Ling,Luo, Qinyu,Yu, Weizhi,Wang, Bo,Shi, Zhang-Jie,Wang, Jianbo
supporting information, p. 4047 - 4050 (2019/04/10)
We report herein an alkenylation of benzylic C(sp3)-H bonds with diazo compounds via carbon cation intermediates with DDQ as the oxidant in the presence of a catalytic amount of Fe(ii). Diphenylmethane, toluene, benzyl methyl sulfide and their derivatives could be applied as substrates to afford the tetra-substituted olefin products, which may serve as useful building blocks in organic synthesis.
Aerobic, Cu-catalyzed desulfitative C-C bond-forming reaction of ketene dithioacetals/vinylogous thioesters and arylboronic acids
Dong, Ying,Wang, Mang,Liu, Jun,Ma, Wei,Liu, Qun
, p. 7380 - 7382 (2011/08/05)
A new Cu-catalyzed thioorganic-boronic acid desulfitative C-C bond-forming reaction involving ketene dithioacetals/ vinylogous thioesters is reported to proceed without the assistance of ligating S-pendant. Vinylogous thiolesters and tetrasubstituted olefins were prepared by this reaction in which Cu catalyst plays a dual role under aerobic conditions.
ELECTROCHEMICAL CYCLIZATION OF TETRAMETHYL ESTERS OF 2-SUBSTITUTED PROPANE-1,1,3,3-TETRACARBOXYLIC ACIDS IN THE PRESENCE OF SALTS OF HYDROHALIC ACIDS
Elinson, M. N.,Fedukovich, S. K.,Nikishin, G. I.
, p. 2523 - 2529 (2007/10/02)
The chemical and electrochemical cyclization of tetramethyl esters of 2-substituted propane-1,1,3,3-tetracarboxylic acids in the presence of hydrohylic acid salt mediators were studied.It was found that the chemical variant of the cyclization of the corresponding α,α'-dianions of esters of propane-1,1,3,3-tetracarboxylic acids by the action of iodine or bromine is substantially inferior to the electrochemical variant.In the latter case, the esters of substituted cyclopropane-1,1,3,3-tetracarboxylic acids are formed in a 87-98percent yield.The tetramethyl ester of 2-isopropylpropane-1,1,3,3-tetracarboxylic acid, which under the electrolysis conditions decomposes according to a Michael retroreaction is an exception.
