Call, Arnau

Arnau Call (1989, Vidreres) obtained his Bachelor’s degree in Chemistry at the Universitat de Girona (UdG) in 2011 receiving the excellence award for academic performance. After that, he coursed the Master’s in Homogenous Catalysis (2012) and PhD (2016) with the FPU graduate fellowship under the supervision of Prof. Julio Lloret. Research work during his PhD involved a 3-month internship at Arizona State University (USA) in the group of Prof. Ghirlanda to develop artificial metalloenzymes. He also performed a 2 years stay at the Institut Català d’Investigació Química (ICIQ) when his supervisor became a group leader at this research center. Arnau also participated in detecting catalytic intermediates at the Diamond Light Source Synchrotron (UK). His PhD project was mainly directed to the development of molecular systems for H2 evolution and for the reduction of organic functionalities using light and water as a source of hydrides. During his PhD he established fruitful collaborations with Prof. Mas-Ballesté and Prof. Pérez-Prieto.

After defending his PhD in December 2016, he moved to the group of Prof. Sakai, at the International Institute for Carbon-Neutral Energy Research (Japan), where he focused on developing photocatalytic systems for CO2 reduction. In January 2021 he returned to the UdG in the group of Prof. Costas as “Juan de la Cierva” research fellow. He has recently performed a 4-month internship at the University of Utah (USA) in the group of Prof. Sigman to implement multivariate linear regression analysis in asymmetric C-H oxidation reactions.

In 2023 he started his independent career in the Universitat de Girona as “Ramon y Cajal” (RyC) researcher. His research interests involve the generation of metal nitrenoid species using light, and their application in the stereoselective amination of C-H bonds. Dr. Call also forms part of the QBIS-CAT group and actively participates in several projects focused on the asymmetric oxidation of C-H bonds.

Nitrene C-H insertion reaction mediated by metal nitrenoid species has emerged as an attractive approach to selectively introduce amino groups. The traditional method for generating such species often relies on the use of nitrene precursors such as organic azides, iminoiodinanes, and dioxazolones, in which elevated temperatures are often required for nitrene generation. The use of high temperatures limits substrate scope and product selectivity.

Photochemical generation of nitrene species offers a potential solution to this issue. While free nitrenes efficiently react with organic compounds, the site-selectivity is mainly dictated and limited by the innate reactivity of the different C-H bonds in the substrate, and the reactions often produce product mixtures. As metal nitrenoid species are envisioned to display higher selectivity than free nitrenes, C-H amination driven by photogenerated metal nitrenoid species is envisioned to allow a control in the selectivity.

Our research project focusses on the development of new methods for generating well-defined metal nitrenoid species under visible light, capable of inducing (stereo)selectivity in C-H amination reactions.