{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

24-08434SR - J Braz Chem Soc Vol 20 No 5 988-992 2009...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Short Report J. Braz. Chem. Soc. , Vol. 20, No. 5, 988-992, 2009. Printed in Brazil - ©2009 Sociedade Brasileira de Química 0103 - 5053 $6.00+0.00 *e-mail: [email protected]; [email protected] Copper Catalyzed Cross-Coupling Reactions of Diaryl Ditellurides with Potassium Aryltrifluoroborate Salts Diego Alves,* ,a Jesus M. Pena, a Adriano S. Vieira, a Giancarlo V. Botteselle, a Rafael C. Guadagnin a and Hélio A. Stefani* ,a,b a Departamento de Farmácia, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, 05508-900 São Paulo-SP, Brazil b Departamento de Biofísica, Universidade Federal de São Paulo, 04023-062 São Paulo-SP, Brazil Apresentamos aqui resultados das reações de acoplamento de diteluretos de diarila com sais de ariltrifluoroborato de potássio, usando quantidades catalíticas de Cu(OAc) 2 e bipiridina, em uma mistura de DMSO/H 2 O, sob ar atmosférico. Estas reações de acoplamento são gerais e são realizadas com diteluretos de diarila e sais de ariltrifluoroborato de potássio contendo substituintes neutros, retiradores e doadores de elétrons, fornecendo os correspondentes teluretos de diarila não simétricos em rendimentos de bons a excelentes. We present here results of the cross-coupling reaction of diaryl ditellurides with potassium aryltrifluoroborate salts using a catalytic amount of Cu(OAc) 2 and bypiridine in DMSO/H 2 O under air atmosphere. This cross-coupling reaction is general and was performed with diaryl ditellurides and potassium aryltrifluoroborate salts bearing electron-withdrawing, electron-donating and neutral substituents, affording the corresponding unsymmetrical diaryl tellurides in good to excellent yields. Keywords: tellurium, trifluoroborate salts, copper catalysis Introduction Chalcogenide compounds have become attractive synthetic targets because of their chemo-, regio-, and stereoselective reactions, 1-4 used in a wide variety of functional groups, thus avoiding protection group chemistry and resulting in useful biological activities. 5-7 Therefore, many classes of organotellurium compounds have been prepared and studied to date and aryl- or vinylic tellurides are certainly the most useful and promising compounds in view of their usefulness in organic synthesis. 8-11 A large number of methodologies have been reported to prepare these compounds. 4,9-11 However, limited synthetic methods are reported to synthesize unsymmetrical diaryl tellurides. In recent years, a transition-metal-catalyzed reaction of diaryl dichalcogenides with aryl halides or boronic acids has become a versatile tool for synthesis of unsymmetrical diaryl chalcogenides. 12-17 Recently, Taniguchi 12 described the preparation of numerous unsymmetrical organotellurides by reaction of organoboronic acids with ditellurides via cleavage of Te-Te bond by a copper catalyst.
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern