Presentation of the most modern and widely used achiral and chiral organic catalysts. Particular attention will be given to enantiomerically pure catalysts and their application in stereoselective synthesis.
Expected learning outcomes
Students will be able to describe mechanisms of the most important organocatalysed reactions. They will learn about the chemical and stereochemical activity of the main metal-free catalysts, broken down by major classes, based on their mechanism of action; and face enantioselective synthesis of chiral organic molecules, taking advantage as a strategy of the use of simple metal-free catalytic systems.
Lesson period: First semester
(In case of multiple editions, please check the period, as it may vary)
The course presents an introduction to general concepts in "green" organic synthesis, the definition of organic catalysts and a general overview of the several reactions promoted by metal-free catalytic systems (8 hours) Then the concept of organocatalyst will be presented, several classes and possible action mechanisms will be considered. The most important examples of metal-free catalysts will be discussed, first in the field of aminocatalysis (8 hours).
Then catalysis through immonium salts, generated by reactions with enantiomerically pure secondary amines will be deeply investigated (8 hours). The use of chiral Lewis bases will be discussed, also in combination with trichlorosilyl derivatives to generate novel chiral Lewis acids (8 hours). Alkaloids derivatives and aminoacids-derived compounds will be also discussed, specially as building blocks for the design and synthesis of bifunctional catalysts (8 hours). Finally phase transfer catalysts and chiral Bronsted acids will be presented as novel organocatalysts (4 hours) Detailed mechanistic investigations on the mode of action of different typologies of chiral oranic catalysts will be discussed. Finally examples of supported organocatalysts will be presented, the recoverability and recyclability of the systems will be discusse ( 4 hours).
Prerequisites for admission
Good knowledge of the basic concepts of Organic Chemistry (I and II)
Traditional Attendance strongly recommended
Reviews and literature articles, and slides given by the Teacher.
Assessement methods and criteria
Oral exam: the exam consists in a discussion about the major classes of catalysts and reactions discussed in the course. Starting from a fairly wide of organocatalysts, the student must explain mechanisms of action and the major steroeselective transformations promoted by those catalytic species, highlighting, if possible, strengths and limitations of the discussed catalytic methodology.