High-Oxidation-State Palladium Catalysis: New Reactivity for Organic Synthesis

Reddy, S. Nitya Sai (2013) High-Oxidation-State Palladium Catalysis: New Reactivity for Organic Synthesis. Masters thesis, Indian Institute of Science Education and Research Kolkata.

PDF (MS Dissertation of S. Nitya Sai Reddy) Nitya_Sai-08MS26-MS_Thesis.pdf - Submitted Version Restricted to Repository staff only Download (6MB)

Abstract

The chemistry of high-valent Palldium is an emerging field. Recently, many imperative reactions involving palladium have been described to have a palladium(IV) intermediate. In this report, the catalytic activity of a complex [(dmbpy)PdCl2] in Suzuki – Miyaura coupling (SMC) reactions has been studied. We propose a PdII/PdIV catalytic cycle during the course of this coupling reaction instead of the conventional Pd0/PdII mechanistic cycle. In order to prove that there is a high-valent palladium intermediate involved in the SMC, attempts were made to isolate the complex through a retro method. The oxidation of an organo-palladium complex helped us take a snapshot of the intermediate through an NMR spectrum. This reaction also gave us several important implications of PdIV in organic synthesis. Our previous catalyst, [(dmbpy)PdCl2], was successful in activating aryl-iodo and aryl-bromo bonds but was unable to activate the aryl-chloro bond. N-heterocylic carbene (NHC) ligands are known to be efficient for this task. In this chapter we here report the synthesis of a novel bis-isonitrile ligand which can mimic the NHC due to its similar electronic structure. The discussion on the possibility of high–valent palladium chemistry with the PdII complex formed with this ligand has also been elaborated.

Actions (login required)

View Item