Green Chemistry in Chemical Education and Synthetic Applications of Sulfinamides

Time: Fri 2020-01-24 10.00

Location: F3, Lindstedtsvägen 26, Stockholm (English)

Subject area: Chemistry

Doctoral student: Björn Blomkvist , Organisk kemi

Opponent: Professor José Alemán, Universidad Autónoma de Madrid, Spain

Supervisor: Associate Professor Peter Dinér, Organisk kemi

Abstract

The preparation of chiral molecules, i.e. compounds that are not identical to their mirror image, is of great interest in the field of organic chemistry. The preparation of a enantiomerically pure molecules is crucial in the development of new pharmaceuticals, agrochemicals and more, since the building blocks of life are chiral and the interactions between enantiomers and receptor are different. Furthermore, an important aspect of chemistry is sustainability, developing new synthetic procedures where green chemistry has been incorporated.

In chapter 2, the use of Brønsted acid catalysis as well as a combined Brønsted acid and aminocatalytic procedure for the preparation of the chiral synthon tert-butane N-sulfinyl imine. Using HBF4•DEE as a catalyst gave the sulfinylimine in high yields in 2 h. Changing the catalyst to HBF4•DEE and aniline both improved the yields and shortened the reaction time to only 30 min. Furthermore, DFT-calculations were performed for both catalytic systems, providing a proposed mechanism suggesting a six-membered cyclic transition state as the key transition state.

In chapter 3 a light-assisted method for the preparation of chiral unnatural amino acids is presented. Via a photoredox-catalyzed decarboxylation of carboxylic acids, a carbon radical is generated that adds stereoselectively to an N-sulfinyl imine. This method allows for green synthesis of non-natural amino acids, and compared to previous methods, we have extended the radical source to include carboxylic acids.

In chapter 4, the use of green chemistry in B.Sc. level teaching is explored through an experimental design project for third-year students, using green chemistry as basis for analysis of literature procedures. Following this, the procedure is implemented in a first-year B.Sc. course. This is proven to be an efficient way to increase the students understanding of organic chemistry, as well as an efficient way to teach green chemistry.

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