Christoforos G. Kokotos was born in Athens, Greece in 1981. He studied chemistry at the National and Kapodistrian University of Athens, Greece (2003), and he completed his PhD studies on chiral sulfur ylides and their applications in the Department of Chemistry at the University of Bristol, UK (2007) under the supervision of Prof. Varinder Aggarwal. After a postdoctoral appointment at the University of Athens, Greece (Prof. George Kokotos) working on primary amine-thioureas as organocatalysts, he moved to Princeton University, USA for further postdoctoral studies working on SOMO organocatalysis in the group of Prof. David W. C. MacMillan. He was elected Lecturer in the Department of Chemistry, University of Athens, Greece in 2010. In 2016, he was promoted to Assistant Professor of Organic Chemistry. His research interests lie on asymmetric organocatalysis, photocatalysis and green methodologies on oxidation reactions and their applications in medicinal chemistry.
The reaction includes activation of H2O2 by 2,2,2trifluoromethylacetophenone, followed by the oxidation of an olefinic group to the corresponding epoxide and intramolecular lactonization affording a variety of substituted γ- or δ-lactones with multiple substitution patterns in good to high yields. The product can be obtained with enough purity after simple extractions, when conversion is quantitative. Attempts to render the process asymmetric met with limited success.
A novel and efficient metal-free catalyzed hydroacylation of dialkyl azodicarboxylates is reported. Graphite flakes were found to be the most efficient catalyst among other carbon-based materials to promote this reaction. This unprecedented catalytic activity can be expanded into a wide substrate scope of aliphatic aldehydes bearing various functional groups, leading to the corresponding products in good to excellent yields.
An organocatalytic and environmentally friendly approach for the selective oxidation of substituted anilines was developed. Utilizing a 2,2,2-trifluoroacetophenone-mediated oxidation process, substituted anilines can be transformed into azoxybenzenes, while a simple treatment with MeCN and H2O2 leads to the corresponding nitro compounds, providing user-friendly protocols that can be easily scaled up. Mechanistic studies utilizing HRMS provide clear evidence for the distinct mechanistic intermediates that are involved. This study constitutes an indirect proof excluding the involvement of a dioxirane intermediate in the green organocatalytic oxidation, utilizing 2,2,2-trifluoroacetophenone as the catalyst.