Asymmetric reactions using chiral monophosphines and novel palladium-catalyzed homocoupling reaction of alkynes and its application in the synthesis of polyynes.

摘要

Asymmetric synthesis has emerged as the method of choice over the past few decades for organic chemists. The preparation of chiral compounds by this method has now become a powerful tool. The usage of enantiopure organic molecules as catalysts has not been investigated to a great extent. This research work describes few asymmetric reactions which were catalyzed by chiral monophosphines. The asymmetric [3+2] cycloaddition reaction of 2,3-butadienoates with electron deficient olefins and N-tosyl imines are summarized in chapter 2.;The palladium-catalyzed cross-coupling reactions are well documented but the homocoupling reactions have not yet been explored to the same extent. Chapter 3 describes a novel palladium-catalyzed homocoupling of alkynes which involves the double transmetallation of palladium enolates.;The palladium-catalyzed homocoupling reaction of alkynes has also been applied towards the synthesis of polycarbynes. The synthesis and characterization of polyynes has been investigated and described in chapter 4.