The Pd-catalyzed semihydrogenation of alkynes to Z-alkenes: Catalyst systems and the type of active species

In this thesis studies have been performed on the Pd-catalyzed Z-selective semihydrogenation of alkynes. In Chapter one a general introduction is given. In Chapter two a new NHC-based, easy-to-use catalyst system is developed. The performance of the system is evaluated for a range of alkynes. In Chapter 3 the operative mechanism according to which this system operates is investigated. In Chapter 4 NHCs based on the natural amino acid histidine are developed and tested in the transfer semi-hydrogenation reaction. In Chapter 5 type of active species for several Pd-catalyzed semihydrogenation reactions is investigated using a protocol that was developed in this chapter.