7497-61-2Relevant articles and documents
Visible-Light-Driven, Metal-Free Divergent Difunctionalization of Alkenes Using Alkyl Formates
Zheng, Ming,Hou, Jing,Zhan, Le-Wu,Huang, Yan,Chen, Ling,Hua, Li-Li,Li, Yan,Tang, Wan-Ying,Li, Bin-Dong
, p. 542 - 553 (2021/01/14)
In recent decades, difunctionalization of alkenes has received considerable attention as an efficient and straightforward way to increase molecular complexity. However, examples of the difunctionalization of alkenes initiated by the intermolecular addition of alkoxycarbonyl radicals providing substituted alkanoates are still rare. Herein, we present the visible light-driven metal-free divergent difunctionalization of alkenes triggered by the intermolecular addition of alkoxycarbonyl radicals under ambient conditions. Employing alkyl formates as precursors of alkoxycarbonyl radicals and 4CzIPN as the photocatalyst, a variety of substituted alkanoates, including β-alkoxy, β-hydroxy, β-dimethoxymethoxy, and β-formyloxy alkanoates, could be facilely accessed with high functional group tolerance and high efficiency. Moreover, the mechanism study revealed that β-hydroxy alkanoates were generated by a selective decomposition of orthoformates promoted by the N-alkoxyazinium salt.
Hydroperoxidations of Alkenes using Cobalt Picolinate Catalysts
Peralta-Neel, Zulema,Woerpel
supporting information, p. 5002 - 5006 (2021/06/30)
Hydroperoxides were synthesized in one step from various alkenes using Co(pic)2as the catalyst with molecular oxygen and tetramethyldisiloxane (TMDSO). The hydration product could be obtained using a modified catalyst, Co(3-mepic)2, with molecular oxygen and phenylsilane. Formation of hydroperoxides occurred through a rapid Co-O bond metathesis of a peroxycobalt compound with isopropanol.
Pentamethylphenyl (Ph*) and Related Derivatives as Useful Acyl Protecting Groups for Organic Synthesis: A Preliminary Study
Cheong, Choon Boon,Frost, James R.,Donohoe, Timothy J.
, p. 1828 - 1832 (2020/10/06)
A study of acyl protecting groups derived from the Ph? motif is reported. While initial studies indicated that a variety of functional groups were not compatible with the Br 2-mediated cleavage conditions required to release the Ph? group, strategies involving the use of different reagents or a modification of Ph? itself (Ph*OH) were investigated to solve this problem.
A Ball-Milling-Enabled Reformatsky Reaction
Cao, Qun,Stark, Roderick T.,Fallis, Ian A.,Browne, Duncan L.
, p. 2554 - 2557 (2019/06/17)
An operationally simple one-jar one-step mechanochemical Reformatsky reaction using in situ generated organozinc intermediates under neat grinding conditions has been developed. Notable features of this reaction protocol are that it requires no solvent, no inert gases, and no pre-activation of the bulk zinc source. The developed process is demonstrated to have good substrate scope (39–82 % yield) and is effective irrespective of the initial morphology of the zinc source.
One-pot enol silane formation-Mukaiyama aldol reactions: Crossed aldehyde-aldehyde coupling, thioester substrates, and reactions in ester solvents
Downey, C. Wade,Dixon, Grant J.,Ingersoll, Jared A.,Fuller, Claire N.,MacCormac, Kenneth W.,Takashima, Anna,Sediqui, Rohina
supporting information, (2019/10/14)
Trimethylsilyl trifluoromethanesulfonate (TMSOTf) and a trialkylamine base promote both in situ enol silane/silyl ketene acetal formation and Mukaiyama aldol addition reactions between a variety of reaction partners in a single reaction flask. Isolation of the required enol silane or silyl ketene acetal is not necessary. For example, crossed aldol reactions between α-disubstituted aldehydes and non-enolizable aldehydes yield β-hydroxy aldehydes in good yield. In a related reaction, the common laboratory solvent ethyl acetate functions as both an enolate precursor and a green reaction solvent. When thioesters are employed as enolate precursors, high yields for additions to non-enolizable aldehydes are routinely observed.
Chiral Nitroarenes as Enantioselective Single-Electron-Transfer Oxidants for Carbene-Catalyzed Radical Reactions
Wang, Hongling,Wang, Yuhuang,Chen, Xingkuan,Mou, Chengli,Yu, Shuyan,Chai, Huifang,Jin, Zhichao,Chi, Yonggui Robin
supporting information, p. 7440 - 7444 (2019/10/02)
A new class of chiral oxidants is developed. These readily accessible oxidants contain a nitro group for oxidation and a chiral sulfonamide moiety for stereoselectivity control. The chiral information from the oxidants can effectively transfer to the substrates in carbene-catalyzed β-hydroxylation of enals via single-electron-transfer radical processes. We expect these oxidants to find unique applications in other asymmetric oxidations and oxygen-atom-transferring reactions.
Method for preparing organoboron compound under catalytic effect of chitosan immobilized copper and application
-
Paragraph 0135; 0136; 0137; 0138; 0139; 0140, (2017/07/21)
The invention discloses a method for preparing an organoboron compound under a catalytic effect of chitosan immobilized copper and an application. The method comprises the following steps: A) adding a chitosan immobilized copper catalyst and a ligand into a reaction tube and stirring; B) respectively continuously adding an initial raw material I and bisdiboron into a system in turn; C) stirring the whole reaction system and reacting under room temperature; D) after the reaction is ended, filtering the whole reaction system, washing with tetrahydrofuran, performing rotary evaporation and concentration on a filtrate, adopting a mixed solvent of ethyl acetate and petroleum ether at different ratios for performing column chromatography on the residues, separating and purifying, thereby acquiring a target product II. The silica gel is taken as a fixing phase for column chromatography. The invention also relates to the application of the prepared organoboron compound in compounding beta-hydroxy compound and anti-cancer drug molecules. The method is feasible; the operation is simple and convenient; the method is suitable for various substrates and can be used for successfully preparing the corresponding target compounds. The catalyst is low in dosage and is recyclable, is easily separated after the ending of the reaction, is free from metal residue and is suitable for large-scale production.
Homoserine lactone derivatives, preparation method thereof and pharmaceutical composition for prevention or treatment of the periodontal diseases containing the same as an active ingredient
-
Paragraph 0147-0150, (2017/04/14)
The present invention relates to homoserine lactone derivatives, optical isomers of the same, or pharmaceutically acceptable salts of the same. The homoserine lactone derivatives in the present invention have excellent properties as a quorum sensing antagonist which hinders communications among bacteria. According to the present invention, the homoserine lactone derivatives can hinder gene expressions of bacteria while effectively blocking formation of biofilm which is known to raise resistance against antibiotics, and suppress propagation of bacteria, thereby being useful as a pharmaceutical composition for preventing or treating periodontal diseases.
A green and recyclable chitosan supported catalyst for the borylation of α,β-unsaturated acceptors in water
Xu, Pengyu,Li, Bojie,Wang, Liansheng,Qin, Caiqin,Zhu, Lei
, p. 23 - 26 (2016/08/09)
We herein report a green and recyclable chitosan supported copper catalyst which is capable of catalyzing the borylation of α,β-unsaturated acceptors in water at room temperature. A broad substrate scope including chalcone derivatives, esters and nitriles have been explored. In all the cases, desired products were obtained in good to excellent yields. Remarkably, this chitosan supported catalyst could be recovered and reused for five times without any significant decrease of reactivity.
Ligand-Promoted, Boron-Mediated Chemoselective Carboxylic Acid Aldol Reaction
Nagai, Hideoki,Morita, Yuya,Shimizu, Yohei,Kanai, Motomu
, p. 2276 - 2279 (2016/06/01)
The first carboxylic acid selective aldol reaction mediated by boron compounds and a mild organic base (DBU) was developed. Inclusion of electron-withdrawing groups in the amino acid derivative ligands reacted with BH3·SMe2 forms a boron promoter with increased Lewis acidity at the boron atom and facilitated the carboxylic acid selective enolate formation, even in the presence of other carbonyl groups such as amides, esters, ketones, or aliphatic aldehydes. The remarkable ligand effect led to the broad substrate scope including biologically relevant compounds.
