sp3 C–H Bond Functionalization with Ruthenium Catalysts

International audienceThe selective formation of carbon–carbon bond by functionalization of an sp3C–H bond is still a challenge in organic synthesis. There are already examples involving transition metal catalysis. In this chapter we review the use of ruthenium(0) and ruthenium(II) catalysts for the formation of carbon–carbon bonds based on creation of reactive sites by sp3C–H bond activation. We show that in most cases, regioselective sp3C–H bond activation is induced either from functional substrates bearing a directing group, which strongly coordinates the metal centre, or by selective C–H bond activation at the α-carbon of a heteroatom accompanied by hydrogen transfer processes and transient creation of reactive functional group

Improved simplicity and practicability in copper-catalyzed alkynylation of tetrahydroisoquinoline

Alkynylation reactions of N-protected tetrahydroisoquinolines have been performed using several different protocols of cross dehydrogenative coupling. Initially, a CuCl-catalyzed method was investigated, which worked well with three different N-protecting groups, namely phenyl, PMP, and benzyl and t-BuOOH as oxidant in acetonitrile as solvent. The peroxide could then be replaced by simple air and acetonitrile for water, leading to an overall very environmentally friendly protocol. Finally, a decarboxylative alkynylation protocol starting from alkynoic acids was also developed using again air as oxidant. This avoids the use of gaseous alkynes in the introduction of short-chained alkyne substituents.Austrian Science Foundation (FWF)911041

Applications of Catalytic Organometallic C(sp3)–H Bond Functionalization

The transition-metal-catalyzed activation of C(sp3)–H bonds has emerged as powerful strategy to create bonds and introduce functional groups in a direct fashion. This review focuses on recent applications of C(sp3)–H bond functionalization strategies to the synthesis of biologically active and natural compounds