5558-66-7Relevant articles and documents
Room Temperature Coupling of Aryldiazoacetates with Boronic Acids Enhanced by Blue Light Irradiation
da Silva, Amanda F.,Afonso, Marco A. S.,Cormanich, Rodrigo A.,Jurberg, Igor D.
supporting information, p. 5648 - 5653 (2020/04/22)
A visible-light-promoted photochemical protocol is reported for the coupling of aryldiazoacetates with boronic acids. This photochemical reaction shows great enhancement compared to the same protocol performed in the absence of light. Except for a few cases, the room temperature coupling in the dark (thermal process) generally does not work. When it does, it is likely to also involve free carbenes as key intermediates. Alternatively, photochemical reactions show a broad scope, can be performed under air and tolerate a wide variety of functional groups. Reaction-evolution monitoring, DFT calculations and control experiments have been used to evaluate the main aspects of this intricate mechanistic scenario. Biologically active molecules Adiphenine, Benactyzine and Aprophen have been prepared as examples of synthetic applications.
Harnessing Applied Potential: Selective β-Hydrocarboxylation of Substituted Olefins
Alkayal, Anas,Buckley, Benjamin R.,Malkov, Andrei V.,Montanaro, Stephanie,Tabas, Volodymyr,Wright, Iain A.
supporting information, (2020/02/13)
The construction of carboxylic acid compounds in a selective fashion from low value materials such as alkenes remains a long-standing challenge to synthetic chemists. In particular, β-addition to styrenes is underdeveloped. Herein we report a new electrosynthetic approach to the selective hydrocarboxylation of alkenes that overcomes the limitations of current transition metal and photochemical approaches. The reported method allows unprecedented direct access to carboxylic acids derived from β,β-trisubstituted alkenes, in a highly regioselective manner.
Palladium(II)-Catalyzed C(sp2)-H Carbonylation of Sterically Hindered Amines with Carbon Monoxide
Cheng, Xiu-Fen,Wang, Tao,Li, Yan,Wu, Yun,Sheng, Jie,Wang, Rui,Li, Chao,Bian, Kang-Jie,Wang, Xi-Sheng
supporting information, p. 6530 - 6533 (2018/10/20)
A palladium-catalyzed, amine-directed C(sp2)-H carbonylation of α,α-disubstituted benzylamine under 1 atm of CO for the facile synthesis of sterically hindered benzolactam has been developed. The key to success is the use of 2,2,6,6-tetramethyl-1-piperidinyloxy as the crucial sole oxidant. The synthetic utility of this transformation has been demonstrated by the first concise synthesis of the natural product spiropachysin-20-one.
Nickel-Catalyzed oxidative coupling of unactivated C(sp3)-H bonds in aliphatic amides with terminal alkynes
Luo, Fei-Xian,Cao, Zhi-Chao,Zhao, Hong-Wei,Wang, Ding,Zhang, Yun-Fei,Xu, Xing,Shi, Zhang-Jie
supporting information, p. 18 - 21 (2017/04/04)
In this work, we demonstrated Ni-catalyzed oxidative coupling of unactivated C(sp3)-H bonds with terminal alkynes for construction of C(sp3)-C(sp) bonds to synthesize alkyl-substituted internal alkynes. Different amides exhibited good compatibility. Preliminary mechanistic studies were conducted to account for this alkynylation.
Nickel-catalysed direct alkylation of thiophenes via double C(sp3)-H/C(sp2)-H bond cleavage: The importance of KH2PO4
Wang, Xie,Xie, Peipei,Qiu, Renhua,Zhu, Longzhi,Liu, Ting,Li, You,Iwasaki, Takanori,Au, Chak-Tong,Xu, Xinhua,Xia, Yuanzhi,Yin, Shuang-Feng,Kambe, Nobuaki
supporting information, p. 8316 - 8319 (2017/07/26)
A Ni-catalyzed oxidative C-H/C-H cross-dehydrogenative coupling (CDC) reaction was developed for constructing various highly functionalized alkyl (aryl)-substituted thiophenes. This method employs thiophenes and aliphatic (aromatic) amides that contain an 8-aminoquinoline as a removable directing group in the presence of a silver oxidant. The approach enables the facile one-step synthesis of substituted thiophenes with high functional group compatibility via double C-H bond cleavage without affecting C-Br and C-I bonds. DFT calculations verify the importance of KH2PO4 as an additive for promoting C-H bond cleavage and support the involvement of a Ni(iii) species in the reaction.
Site-Selective Catalytic Carboxylation of Unsaturated Hydrocarbons with CO2 and Water
Gaydou, Morgane,Moragas, Toni,Juliá-Hernández, Francisco,Martin, Ruben
supporting information, p. 12161 - 12164 (2017/09/12)
A catalytic protocol that reliably predicts and controls the site-selective incorporation of CO2 to a wide range of unsaturated hydrocarbons utilizing water as formal hydride source is described. This platform unlocks an opportunity to catalytically repurpose three abundant, orthogonal feedstocks under mild conditions.
Bridging C?H Activation: Mild and Versatile Cleavage of the 8-Aminoquinoline Directing Group
Berger, Martin,Chauhan, Rajan,Rodrigues, Catarina A. B.,Maulide, Nuno
supporting information, p. 16805 - 16808 (2016/11/16)
8-Aminoquinoline has emerged as one of the most powerful bidentate directing groups in history of C?H activation within the last decade. However, cleavage of its robust amide bond has shown to be challenging in several cases, thus jeopardizing the general synthetic utility of the method. To overcome this limitation, we herein report a simple oxidative deprotection protocol. This transformation rapidly converts the robust amide to a labile imide, allowing subsequent cleavage in a simple one-pot fashion to rapidly access carboxylic acids or amides as final products.
Hydrodecarboxylation of Carboxylic and Malonic Acid Derivatives via Organic Photoredox Catalysis: Substrate Scope and Mechanistic Insight
Griffin, Jeremy D.,Zeller, Mary A.,Nicewicz, David A.
supporting information, p. 11340 - 11348 (2015/09/21)
A direct, catalytic hydrodecarboxylation of primary, secondary, and tertiary carboxylic acids is reported. The catalytic system consists of a Fukuzumi acridinium photooxidant with phenyldisulfide acting as a redox-active cocatalyst. Substoichiometric quantities of Hünigs base are used to reveal the carboxylate. Use of trifluoroethanol as a solvent allowed for significant improvements in substrate compatibilities, as the method reported is not limited to carboxylic acids bearing α heteroatoms or phenyl substitution. This method has been applied to the direct double decarboxylation of malonic acid derivatives, which allows for the convenient use of dimethyl malonate as a methylene synthon. Kinetic analysis of the reaction is presented showing a lack of a kinetic isotope effect when generating deuterothiophenol in situ as a hydrogen atom donor. Further kinetic analysis demonstrated first-order kinetics with respect to the carboxylate, while the reaction is zero-order in acridinium catalyst, consistent with another finding suggesting the reaction is light limiting and carboxylate oxidation is likely turnover limiting. Stern-Volmer analysis was carried out in order to determine the efficiency for the carboxylates to quench the acridinium excited state.
Direct lactonization of 2-arylacetic acids through Pd(II)-catalyzed C-H activation/C-O formation
Yang, Mingyu,Jiang, Xingyu,Shi, Wen-Juan,Zhu, Qi-Lei,Shi, Zhang-Jie
supporting information, p. 690 - 693 (2013/04/10)
Palladium-catalyzed direct lactonization of 2-arylacetic acids through a reaction sequence that includes C-H activation/C-O formation is reported. This method provides a concise and efficient pathway to synthesize fully functionalized benzofuranone derivatives, which are highly relevant to bioactive natural and synthetic products.
Dirhodium(II) tetrakis[N-tetrafluorophthaloyl-(S)-tert-leucinate]: An exceptionally effective Rh(II) catalyst for enantiotopically selective aromatic C-H insertions of diazo ketoesters
Tsutsui, Hideyuki,Yamaguchi, Yukiko,Kitagaki, Shinji,Nakamura, Seiichi,Anada, Masahiro,Hashimoto, Shunichi
, p. 817 - 821 (2007/10/03)
Dirhodium(II) tetrakis[N-tetrafluorophthaloyl-(S)-tert-leucinate], Rh2[(S)-TFPTTL]4, in which the phthalimido hydrogen atoms of the parent dirhodium(II) complex are substituted by fluorine atoms, dramatically enhances the reactivity and enantioselectivity (up to 97% ee) in intramolecular aromatic C-H insertion reactions of methyl 4-alkyl-2-diazo-4,4-diphenyl-3-oxopropionates. Catalysis with the use of 0.001 mol% of Rh2[(S)-TFPTTL]4 has achieved the highest turnover number (up to 98,000 with the methyl substituent) ever recorded for chiral dirhodium(II) complex-catalyzed carbene transformations, without compromising the yield or enantioselectivity of the process.
