174813-84-4Relevant articles and documents
Photochemical C-H Activation Enables Nickel-Catalyzed Olefin Dicarbofunctionalization
Campbell, Mark W.,Yuan, Mingbin,Polites, Viktor C.,Gutierrez, Osvaldo,Molander, Gary A.
supporting information, p. 3901 - 3910 (2021/04/06)
Alkenes, ethers, and alcohols account for a significant percentage of bulk reagents available to the chemistry community. The petrochemical, pharmaceutical, and agrochemical industries each consume gigagrams of these materials as fuels and solvents each year. However, the utilization of such materials as building blocks for the construction of complex small molecules is limited by the necessity of prefunctionalization to achieve chemoselective reactivity. Herein, we report the implementation of efficient, sustainable, diaryl ketone hydrogen-atom transfer (HAT) catalysis to activate native C-H bonds for multicomponent dicarbofunctionalization of alkenes. The ability to forge new carbon-carbon bonds between reagents typically viewed as commodity solvents provides a new, more atom-economic outlook for organic synthesis. Through detailed experimental and computational investigation, the critical effect of hydrogen bonding on the reactivity of this transformation was uncovered.
Electrochemical Arylation of Aldehydes, Ketones, and Alcohols: from Cathodic Reduction to Convergent Paired Electrolysis
Zhang, Sheng,Li, Lijun,Li, Jingjing,Shi, Jianxue,Xu, Kun,Gao, Wenchao,Zong, Luyi,Li, Guigen,Findlater, Michael
supporting information, p. 7275 - 7282 (2021/03/01)
Arylation of carbonyls, one of the most common approaches toward alcohols, has received tremendous attention, as alcohols are important feedstocks and building blocks in organic synthesis. Despite great progress, there is still a great gap to develop an ideal arylation method featuring mild conditions, good functional group tolerance, and readily available starting materials. We now show that electrochemical arylation can fill the gap. By taking advantage of synthetic electrochemistry, commercially available aldehydes (ketones) and benzylic alcohols can be readily arylated to provide a general and scalable access to structurally diverse alcohols (97 examples, >10 gram-scale). More importantly, convergent paired electrolysis, the ideal but challenging electrochemical technology, was employed to transform low-value alcohols into more useful alcohols. Detailed mechanism study suggests that two plausible pathways are involved in the redox neutral α-arylation of benzylic alcohols.
Dual-Role Catalysis by Thiobenzoic Acid in Cα-H Arylation under Photoirradiation
Kobayashi, Fumihisa,Fujita, Masashi,Ide, Takafumi,Ito, Yuta,Yamashita, Kenji,Egami, Hiromichi,Hamashima, Yoshitaka
, p. 82 - 87 (2021/01/11)
Thiobenzoic acid (TBA) can serve as a single-electron reducing agent under photoirradiation from a blue light-emitting diode, in the presence of appropriate electron acceptors, and the resulting sulfur-centered radical species undergoes hydrogen atom abstraction. This dual-role catalysis by TBA enables regioselectivie Cα-H arylation of benzylamines, benzyl alcohols, and ethers, as well as dihydroimidazoles, with cyano(hetero)arenes in good yield, without the need for a transition-metal photocatalyst and/or synthetically elaborated organic dyes.
An Efficient Ga(OTf)3/Isopropanol Catalytic System for Direct Reduction of Benzylic Alcohols
Sai, Masahiro
supporting information, p. 4330 - 4335 (2018/10/15)
This study aims to report the first gallium-catalyzed direct reduction of benzylic alcohols using isopropanol as a reductant. The reaction proceeds via gallium catalyst-assisted hydride transfer of the in situ-generated benzylic isopropyl ether. The method generates only water and acetone as byproducts and thus provides an atom-economic and environmentally friendly approach to the synthesis of di- and triarylmethanes, which are important substructures in various bioactive compounds and functional materials. (Figure presented.).
Sulfonamides as new hydrogen atom transfer (HAT) catalysts for photoredox allylic and benzylic C-H arylations
Tanaka, Hirotaka,Sakai, Kentaro,Kawamura, Atsushi,Oisaki, Kounosuke,Kanai, Motomu
supporting information, p. 3215 - 3218 (2018/04/05)
A catalytic amount of a sterically and electronically tuned diarylsulfonamide promoted allylic and benzylic C-H arylations in cooperation with a visible light photoredox catalyst. This is the first example of the catalytic use of a sulfonamidyl radical to promote the hydrogen atom transfer process.
Photo-induced reductive cross-coupling of aldehydes, ketones and imines with electron-deficient arenes to construct aryl substituted alcohols and amines
Liu, Zan,Nan, Xiaolei,Lei, Tao,Zhou, Chao,Wang, Yang,Liu, Wenqiang,Chen, Bin,Tung, Chenho,Wu, Lizhu
, p. 487 - 494 (2018/03/22)
Umpolung reactions of C=X bonds (X = O, N) are valuable ways of constructing new C–C bonds, which are sometimes difficult to be constructed using traditional synthetic pathways. Classical polarity inversion of C=X bonds (X = O, N) usually requires air or moisture-sensitive and strong reducing agents, which limit the feasibility of substrate scope. Herein we describe a photo-induced reductive cross-coupling reaction of aldehydes, ketones and imines with electron-deficient arenes (aromatic nitriles) using fac-Ir(ppy)3 as a photocatalyst and diisopropylethylamine (DIPEA) as a terminal reductant under visible light irradiation. Mild conditions and high yields mean that this new polarity inversion strategy can be used with aryl-substituted alcohols and amines. Spectroscopic studies and control experiments have demonstrated the oxidative quenching of Ir(ppy)3* by electron-deficient arenes involved in the key step for the C–C bond formation.
Visible-Light-Triggered Directly Reductive Arylation of Carbonyl/Iminyl Derivatives through Photocatalytic PCET
Chen, Ming,Zhao, Xinxin,Yang, Chao,Xia, Wujiong
supporting information, p. 3807 - 3810 (2017/07/26)
The first visible-light-mediated radical-radical cross-coupling strategy that enables the direct arylation of carbonyl/iminyl derivatives in the presence of Et3N has been realized. Such an atom-economical protocol furnishes a broad scope of arylation products such as secondary/tertiary alcohols and amines via a PCET process that facilitates the challenging reduction of C-X (X = O, N). Mechanistic investigation indicates two photocatalytic redox cycles were involved in the process, and Et3N was proved to serve as a dual reductant and proton donor. Moreover, the isolated byproducts and controlled experiments could be considered as powerful supporting evidence for our hypothesis.
Anionic four-electron donor-based palladacycles as catalysts for addition reactions of arylboronic acids with α,β-unsaturated ketones, aldehydes, and α-ketoesters
He, Ping,Lu, Yong,Dong, Cheng-Guo,Hu, Qiao-Sheng
, p. 343 - 346 (2007/10/03)
(Chemical Equation Presented) Anionic four-electron donor-based palladacycle-catalyzed 1,4-additions of arylboronic acids with α,β-unsaturated ketones and 1,2-additions of arylboronic acids with aldehydes and α-ketoesters are described. Our study demonstrated that palladacycles were highly efficient, practical catalysts for these addition reactions. The work described here not only opened a new paradigm for the application of palladacycles, but may also pave the road for other metalacycles as practically useful catalysts for such addition reactions including asymmetric ones.
t-Bu-Amphos-RhCl3·3H2O: A highly recyclable catalyst system for the cross-coupling of aldehydes and aryl- and alkenylboronic acids in aqueous solvents
Huang, Rongcai,Shaughnessy, Kevin H.
, p. 4484 - 4486 (2007/10/03)
The combination of t-Bu-Amphos and RhCl3·3H2O gave the first highly recyclable catalyst for the coupling of aryl- and vinylboronic acids with aldehydes in aqueous solvents. The Royal Society of Chemistry 2005.
Rhodium-catalyzed addition of aryl- and alkenylsilanediols to aldehydes
Fujii, Toshinari,Koike, Tooru,Mori, Atsunori,Osakada, Kohtaro
, p. 298 - 300 (2007/10/03)
Arylation and alkenylation of aromatic aldehydes with silanediols is shown to proceed by use of a catalytic amount of rhodium complex. Treatment of ethyl(4-methoxyphenyl)silanediol with benzaldehyde in the presence of 3 mol% of [Rh(OH)(cod)]2 a
