42599-18-8Relevant academic research and scientific papers
Rapid Access to Highly Functionalized Alkyl Boronates by NiH-Catalyzed Remote Hydroarylation of Boron-Containing Alkenes
Zhang, Yao,Han, Bo,Zhu, Shaolin
supporting information, p. 13860 - 13864 (2019/08/08)
The direct and selective functionalization of relatively simple and readily accessible precursors to produce highly functionalized alkyl boronates is a synthetically useful process. Herein we report a NiH-catalyzed remote hydroarylation process that can, through a synergistic combination of chain walking and subsequent cross-coupling, introduce an aryl group at the adjacent carbon atom of alkyl boronates under mild conditions. By means of a preliminary experiment with moderate enantioselectivity, it was shown that an asymmetric version could also be realized.
A Tunable Route to Prepare α,β-Unsaturated Esters and α,β-Unsaturated-γ-Keto Esters through Copper-Catalyzed Coupling of Alkenyl Boronic Acids with Phosphorus Ylides
Bi, Hong-Yan,Liu, Feng-Ping,Liang, Cui,Su, Gui-Fa,Mo, Dong-Liang
supporting information, p. 1510 - 1516 (2018/03/05)
A tunable strategy to prepare α,β-unsaturated esters and α,β-unsaturated-γ-keto esters in good to excellent yields was developed through copper-catalyzed oxidative coupling of phosphorus ylides with alkenyl boronic acids under mild conditions. The reaction without water afforded α,β-unsaturated esters, ketones, and amides while α,β-unsaturated-γ-keto esters, 1,4-α,β-unsaturated diketones and α,β-unsaturated-γ-keto amides were obtained when using 5.0 equiv. of water. H2O18 labeling experiments showed that water played an important role in the formation of α,β-unsaturated-γ-keto esters. A plausible formation mechanism for α,β-unsaturated esters and α,β-unsaturated-γ-keto esters was proposed based on mechanistic studies. Phosphonium salts could also be used directly as coupling partners instead of phosphorus ylides. The reaction exhibited a broad substrate scope, good functional group tolerance, good regioselectivity, and diverse coupling products. (Figure presented.).
Regioselectivity of 1,3-Dipolar Cycloadditions of Benzonitrile Oxide to Alkenyl Boronic Esters: An Experimental and Computational Study
Jeong, Jo,Zong, Kyukwan,Choe, Joong Chul
, p. 1007 - 1014 (2017/03/27)
1,3-Dipolar cycloaddition reactions of benzonitrile oxide to monosubstituted or 1,1-disubstituted alkenyl boronic ester gave only 2-isoxazolines, bearing the boronic ester group at the 5-position of the ring. On the other hand, the cycloaddition reactions of benzonitrile oxide with trans-1,2-disubstituted alkenyl boronic esters produced 2-isoxazolines, bearing the boronic ester group at the 4-position of the ring. We used quantum mechanical calculations to investigate two regioisomeric channels that were associated with the formation of 2-isoxazolines, bearing the boronic ester group at the 4-position or 5-position. The study revealed that the experimental results agreed well with the parameters based on the transition state energies in gas or solvent phase. The study also informed that all the cycloaddition reactions proceed in a spontaneous and exergonic fashion.
ASYMMETRIC ADDITION REACTIONS
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Paragraph 00134, (2016/12/26)
Processes of forming Csp2-Csp3 bonds at the allylic carbon of a cyclic allylic compound starting material are disclosed, in which a racemic mixture of a cyclic allylic compound having a leaving group attached to the allylic carbon is reacted with a compound having a nucleophilic carbon atom in the presence of a Rh(l), Pd(ll) or Cu(l) pre-catalyst and a chiral ligand. The reaction products containing the newly-formed Csp2-Csp3 bond are generated in high stereoisomeric excess, and may therefore serve as important organic building blocks in the preparation of new agrochemicals and pharmaceuticals.
N-B dative bond-induced [3.3.0] bicyclic boronate-tethered exo-selective intramolecular Diels-Alder reaction
Feng, Chao,Wang, Hong,Xu, Liang,Li, Pengfei
supporting information, p. 7136 - 7139 (2015/07/01)
We report herein a highly exo-selective intramolecular Diels-Alder reaction of alkenyl boronates which employs an N-B dative bond-involved bicyclic rigid tether. Complex C(sp3)-rich polycyclic molecules containing up to 8 stereocenters can be readily formed via an operationally simple two-step procedure.
Liebeskind-Srogl cross-coupling on γ-carboxyl-γ-butyrolactone derivatives: Application to the side chain of amphidinolides C and F
Fenneteau, Johan,Vallerotto, Sara,Ferrié, Laurent,Figadère, Bruno
supporting information, p. 3758 - 3761 (2015/06/08)
The synthetic approach for the C20-C29 and C20-C34 fragments of amphidinolide F and C was based on an original Liebeskind-Srogl cross-coupling reaction with a glutamic acid-derived building-block. Further highly diastereoselective reduction of the ketone was achieved by using an uncommon Ph3SiH/TBAF/HMPA system. The amphidinolide C side chain was built through a reductive elimination of chiral epoxide to install the stereogenic center at C29.
Microwave-assisted Suzuki-Miyaura cross-coupling of 2-alkyl and 2-alkenyl-benzo-1,3,2-diazaborolanes
Hadebe, Siphamandla W.,Sithebe, Siphamandla,Robinson, Ross S.
scheme or table, p. 4277 - 4282 (2011/06/26)
Nitrogen-based boronate esters, such as 2-octyl-benzo-1,3,2-diazaborolane, 2-phenethyl-benzo-1,3,2-diazaborolane, and 2-{(1E)-hexenyl}-benzo-1,3,2- diazaborolane have been shown to be suitable coupling partners with arylhalides in microwave accelerated Suzuki cross-coupling reactions. Reaction yields of up to 89% were achieved. The use of a silicon group attached to the nitrogen atom, proved to enhance the reactivity of 2-octyl-benzo-1,3,2-diazaborolane.
A convenient catalyst for aqueous and protein Suzuki-Miyaura cross-coupling
Chalker, Justin M.,Wood, Charlotte S. C.,Davis, Benjamin G.
supporting information; experimental part, p. 16346 - 16347 (2010/01/29)
(Figure Presented) A phosphine-free palladium catalyst for aqueous Suzuki-Miyaura cross-coupling is presented. The catalyst is active enough to mediate hindered, ortho-substituted biaryl couplings but mild enough for use on peptides and proteins. The Suzuki-Miyaura couplings on protein substrates are the first to proceed in useful conversions. Notably, hydrophobic aryl and vinyl groups can be transferred to the protein surface without the aid of organic solvent since the aryl- and vinylboronic acids used in the coupling are water-soluble as borate salts. The convenience and activity of this catalyst prompts use in both general synthesis and bioconjugation.
Facile synthesis of iodonium salts by reaction of organotrifluoroborates with p-iodotoluene difluoride
Yoshida, Masanori,Osafune, Kanako,Hara, Shoji
, p. 1542 - 1546 (2008/02/05)
A simple and easy method for the synthesis of various iodonium salts was developed, and involves the reaction of potassium organotrifluoroborates with p-iodotoluene difluoride under mild conditions. The one-pot synthesis of a (Z)-(2-fluoroalkenyl)iodonium
