Advances in Transition-Metal-Catalyzed Direct sp3-Carbon–Hydrogen Bond Functionalization

Abstract

Transition-metal-catalyzed direct carbon-hydrogen bond functionalization has made significant advances in the field of carbonhydrogen bond activation over the past decades. This methodology has the potential to be used in many different areas of chemistry; for example, it can provide an opportunity for the synthesis of various kinds of complex compounds. This account mainly focuses on recent advances in transition-metal-catalyzed direct sp 3 -carbon-hydrogen bond functionalization to form carbon-carbon bonds. 1 Introduction 2 Carbon-Carbon Bond Formation via Direct sp 3 -Carbon-Hydrogen Bond Functionalization 2.1 Coupling of sp 3 -Carbon-Hydrogen and sp-Carbon-Hydrogen Bonds 2.2 Coupling of sp 3 -Carbon-Hydrogen and sp 2 -Carbon-Hydrogen Bonds 2.3 Coupling of sp 3 -Carbon-Hydrogen and sp 3 -Carbon-Hydrogen Bonds 2.4 Coupling of sp 3 -Carbon-Hydrogen and C-X Bonds 3 Conclusion Key words transition metals, catalysis, carbon-carbon bond formations, cross-dehydrogenative coupling, direct bond functionalizations Carbon-Carbon Bond Formation via Direct sp 3 -Carbon-Hydrogen Bond FunctionalizationThe oxidative coupling of two different carbon-hydrogen bonds was termed cross-dehydrogenative coupling (CDC) by Li's group 4 in 2004, and it has become an increasing field of interest. In the past decade, a growing number of efficient procedures and novel methods have been introduced. These methods make the connection of sp 3 -carbonhydrogen with sp-carbon-hydrogen, sp 2 -carbon-hydrogen, sp 3 -carbon-hydrogen, and C-X bonds a reality (Scheme 1). 4,5 However, the development of chemo-, regio-, and stereoselective sp 3 -carbon-carbon bond formation reactions is still one of the most challenging tasks in organic synthesis.