Hydrogen bond donors in non-classical asymmteric catalysis

From Bioorganic
Jump to: navigation, search
ACAT.jpg

Principal Investigator: Rafał Kowalczyk

Team:

Żaneta A. Ignatiuk (PhD student)

Maciej Dajek (PhD student)

Agnieszka Pruszczyńska (MSc student)

Dominika A. Andrzejczyk (MSc student)

Szymon P. Ślusarczyk (MSc student)

Aleksandra Motyka (MSc student)

Wojciech Piekarski (MSc student)

Radosław W. Suchanek (MSc student)


Project financed by National Science Centre, no. 2016/22/E/ST5/00046

Starting date: April 12th, 2017

Duration: 60 months

Budget: 1 304 481 PLN

Abstract

Project goal

The project is focused on the application of more sustainable and thus non-classical methods in asymmetric catalysis. Hydrogen bond donors which structure will be tuned for specific task are the main group of catalysts. Among the activation methods, ball-milling, microwave-assisted processes and the application of hydrophobic amplification will be particularly developed.

Background and motivation

The exhaustion of natural resources is being watched with great concern. Therefore, requirements on different types of economy for new and old chemical processes are being imposed. For modern organic chemistry the key to overcome these challenges is seen in catalysis. Spectacular examples include very efficient processes using just tiny amounts of catalyst, preferably without the need for rare metals. Among many notable purely organic catalysts, squaramides show impressive activity even at 0.01-2 mol% loading. With such a such a small amount it is possible to perform few sequential reactions in a single vessel. This approach is saving both time and energy, and most importantly alleviates the need for tedious and wasteful isolation and purification of the intermediate products. Another way to improve efficiency of organic synthesis is to use simple and non-functionalized substrates and apply them in a C(sp3)-H activation. This challenging approach can allow using more available starting materials, and circumvent multistep pre-functionalization, which was a traditional art of making complex molecules. One of the ways of direct activation of relatively inert C(sp3)-H bond can be effected by oxidation. This can be achieved even with non-metallic oxidant. In the process, a cation intermediate is formed; and its reactivity can be controlled. The cation can form a compact ion pair with a nucleophile. While the task of a catalyst is to first bind the nucleophile, and as a consequence of tight ion pair formation, also an electrophile. With an asymmetric catalyst the reaction will proceed in a chiral environment giving rise to stereoselectivity. The aim of the project is to develop a group of organic catalysts to effectively control the stereochemical course of C(sp3)-H activation. Moreover, more sustainable techniques of activation of organic compounds will be applied in the catalytic asymmetric transformations in which hydrogen bond donors will play pivotal role.

Project on ResearchGate