1.Ni/Cu-Catalyzed Defluoroborylation of Fluoroarenes for Diverse C-F Bond Functionalizations.
Niwa T1, Ochiai H1, Watanabe Y1, Hosoya T1. J Am Chem Soc. 2015 Nov 18;137(45):14313-8. doi: 10.1021/jacs.5b10119. Epub 2015 Nov 3.
Ni/Cu-catalyzed transformation of fluoroarenes to arylboronic acid pinacol esters via C-F bond cleavage has been achieved. Further versatile derivatization of an arylboronic ester has allowed for the facile two-step conversion of a fluoroarene to diverse functionalized arenes, demonstrating the synthetic utility of the method.
2.Ligand-Promoted Rh(III)-Catalyzed Coupling of Aryl C-H Bonds with Arylboron Reagents.
Wang HW1, Cui PP1, Lu Y1, Sun WY1, Yu JQ2. J Org Chem. 2016 Apr 15;81(8):3416-22. doi: 10.1021/acs.joc.6b00083. Epub 2016 Apr 7.
Rhodium(III)-catalyzed C-H arylation of arenes with phenylboronic acid pinacol esters has been achieved using a readily removable N-pentafluorophenylbenzamide directing group for the first time. The use of a bidentate phosphine ligand (Binap) significantly increased the yield of the cross-coupling of C-H bonds with organoboron reagents.
3.Alternating Intramolecular and Intermolecular Catalyst-Transfer Suzuki-Miyaura Condensation Polymerization: Synthesis of Boronate-Terminated π-Conjugated Polymers Using Excess Dibromo Monomers.
Nojima M1, Kosaka K1, Kato M1, Ohta Y1, Yokozawa T1. Macromol Rapid Commun. 2015 Oct 28. doi: 10.1002/marc.201500587. [Epub ahead of print]
The Suzuki-Miyaura coupling polymerization of dibromoarene 1 and arylenediboronic acid (ester) 2 with a Pd catalyst having a high propensity for intramolecular catalyst transfer is reported. The polymerization of excess 1 with 2 affords high-molecular-weight π-conjugated polymer having boronic acid (ester) moieties at both ends, contrary to Flory's principle. This unstoichiometric polycondensation behavior is accounted for by intramolecular transfer of the Pd catalyst on 1. In the polymerization of 1 and 2 having different aryl residues, high-molecular-weight polymer is obtained when the stronger donor aromatic is used as the dibromo monomer and the weaker donor or acceptor aromatic is used as diboronic acid (ester) monomer. The pinacol boronate moieties at both ends of the obtained poly(p-phenylene) (PPP) can be converted to benzoic acid ester, hydroxyl group, and bromine. Furthermore, the reaction of the pinacol boronate-terminated PPP with poly(3-hexylthiophene) (P3HT) having bromine at one end yields a triblock copolymer of P3HT-b-PPP-b-P3HT.
4.Preparing (Multi)Fluoroarenes as Building Blocks for Synthesis: Nickel-Catalyzed Borylation of Polyfluoroarenes via C-F Bond Cleavage.
Zhou J1,2, Kuntze-Fechner MW2, Bertermann R2, Paul US2, Berthel JH2, Friedrich A2, Du Z1, Marder TB2, Radius U2. J Am Chem Soc. 2016 Apr 18. [Epub ahead of print]
The [Ni(IMes)2]-catalyzed transformation of fluoroarenes into arylboronic acid pinacol esters via C-F bond activation and transmetalation with bis(pinacolato)diboron (B2pin2) is reported. Various partially fluorinated arenes with different degrees of fluorination were converted into their corresponding boronate esters.