Construction of Carbon-Heteroatom and Heteroatom-Heteroatom bonds using Iodine and Zinc catalysts

Abstract

The thesis entitled “Construction of Carbon-Heteroatom and Heteroatom-Heteroatom bonds using Iodine and Zinc catalysts” has been divided into five chapters. Chapter 1 describes a general introduction to iodine, hyper-valent iodine, and zinc chemistry. Chapters 2, 3, 4 are in Section A. Chapters 2 and 3 describe the role of iodine for C-N and C-S bond formation. Chapter 4 describes the utility of hyper-valent iodine for N-S bond formation. Last chapter 5 is covered under Section B, where zinc catalyst has been used for C-N bond formation. Section A, chapter 2 describes the role of iodine in the C-H functionalization of cyclopentenedione with benzamidine hydrochloride, which leads to fused imidazole derivatives in the presence of iodine/TBHP combination in a short period of time. To support the reaction mechanism, mass spectrometric analysis has been carried out. Section A, chapter 3 covers a multicomponent strategy for C-N and C-S bond formation using thiols, benzaldehydes and trimethoxybenzene using a catalytic amount of iodine. Section A, chapter 4 deals with trifluoromethylsulfonylation of pyrazolone using hypervalent iodine PIFA, which leads to N-triflination instead of C-4 functionalization of pyrazolone. The reaction completes in 5 minutes, leading to a new N-S bond. Section B, chapter 5, represents zinc-mediated C-N bond formation using cinnamyl alcohol and 2-amino pyridines. In this method, ZnBr2 acts as a Lewis acid. The method was found to be compatible with primary alcohol, secondary alcohol as well as homoallyl alcohol.