Ribas, Xavi

Xavi Ribas (1974, Santa Coloma de Farners) obtained his PhD in Chemistry at the University of Girona (UdG) in 2001, and he carried out a 3-year postdoc at ICMAB-CSIC in 2002-2004. He was promoted to Associate professor in Chemistry at UdG in 2006. His research over the last years has been focused on three main projects; a) Fundamental mechanistic studies on redox transition metals in organometallic cross coupling and C-H activation and functionalization of arenes, b) Study of structural and functional modelling of non-heme Fe, Mn and Cu oxygenases and its application as selective oxidation catalysts, c) development of nanocapsules for catalysis at the confined space, host-guest reactions and purification of fullerenes and endohedral metallofullerenes (EMFs).

He was awarded with an ICREA-Acadèmia prize in 2010, and an ERC-Starting Grant in 2011 (ERC-2011-StG-277801, till Nov 2017), the latter on C-X and C-H functionalization involving Cu(III) species. Moreover, he obtained two consecutive grants from MINECO (CTQ2013-43012-P, CTQ2016-77989-P). He was awarded with a second ICREA-Acadèmia prize in 2015, and an ERC-Proof of Concept Grant in 2015 (ERC-PoC-2015-709590). He is also leading the Catalan project (2017 SGR 264), and the Univ. Girona research projects MCPUdG2016 and GdRCompetUdG2017. In 2018 he was awarded with the Premio a la Excelencia Investigadora RSEQ 2018.

His work has been published in 123 articles in peer reviewed journals. Moreover, he published 5 book chapters, filled 5 Spanish patents and he edited the book entitled “C-H and C-X functionalization. Transition metal mediation”, published by RSC-Publishing in 2013. He has communicated his work in more than 170 international conferences and he has given over 45 lectures at international conferences and universities. He is also the co-founder of the SpinOff company GIOXCAT.

Copper-catalyzed cross-coupling reactions for the formation of aryl?heteroatom bonds (Ullmann reaction) is currently a hot topic, due to the importance of developing new sustainable synthetic tools. However, several mechanistic key aspects are still under debate. Our goal is to design new catalysts capable of effecting the desired transformations under mild conditions. A breakthrough finding of our group has been the recognition of the Cu(I)/Cu(III) catalytic redox cycle as a viable mechanism in Ullmann-type catalysis. This coupling reactivity has been extended for the first time to the other coinage metals, i.e. Ag(I)/Ag(III) and Au(I)/Au(III) catalytic cycles. Our research interests also involve the development and mechanistic understanding of C-H activation catalyzed by cheaper and less toxic first-row transition metal, especially Co and Ni. Finally, the catalytic procedures are explored in confined environments using supramolecular metallocages, including asymmetric transformations via organometallic catalysis and the purification of fullerenes and EMFs.

Sustainable C-X and C-H functionalization catalyzed by first-row transition metals.

Metal-catalyzed cross-coupling reactions for the formation of aryl?heteroatom bonds is a hot topic, due to the importance of developing new sustainable synthetic tools. However, several mechanistic key aspects are still under debate. Our goal is to design new catalysts capable of effecting the desired transformations under mild conditions. A breakthrough finding of our group has been the recognition of the Cu(I)/Cu(III) catalytic redox cycle as a viable mechanism in Ullmann-type catalysis. Analogous Ag(I)/Ag(III) and Au(I)/Au(III) redox catalysis are also under investigation. The development of more sustainable direct C-H functionalization reactions, catalyzed by transition-metals, is another enormous challenge. Our research is focused on the quest of cheaper and less toxic first-row transition metal activation of C-H bonds, with the understanding of the molecular mechanism of such transformations as a major goal.

Catalysis in the confined space

The supramolecular design of 3D nanocapsules is pursued through metal-driven self-assembly, with potential applications as reaction nanovessels and supramolecular hosts. Along this strategy, we have been able to synthesize a variety of structures that include molecular nanosized squares and rectangles, helicates and trigonal and tetragonal prismatic nanocapsules. We have been able to demonstrate the effectiveness of asymmetric hydroformylation catalyzed by anchored Rh-catalysts using metalloporphyrin-containing tetragonal prismatic nanocapsules. Moreover, the host-guest properties of nanocapsules are currently being exploited in the purification of fullerenes and EMFs, and in their regioselective functionalization by taking advantage of the use of nanocapsules as supramolecular masks.

• 

  Xavier Ribas

  Full Professor

  

• 

  Josep Esteve

  Postdoc

  Supervisor
  - M. Costas
• 

  Valentina Iannace

  Postdoc

  Supervisor
  - X. Ribas
• 

  Carles Fuertes

  Postdoc (BP)

  Supervisor
  - M. Costas, X. Ribas

• 

  Judith Sala

  PhD Student (FI)

  Supervisor
  - X. Ribas
• 

  Clara Sabrià

  PhD Student (IF-UdG)

  Supervisor
  - F. Feixas, X. Ribas
• 

  Piyush Piyush

  PhD Student (FPI)

  Supervisor
  - X. Ribas
• 

  Tània Pèlachs

  PhD Student (FPU)

  Supervisor
  - X. Ribas
• 

  Nora Alpuente

  PhD Student (IF-UdG)

  Supervisor
  - X. Ribas

Collaboration with Xavier Ribas

• Luis Echegoyen – University of Texas (United States)