Nickel-catalyzed asymmetric cross-couplings of secondary alkyl electrophiles and photoinduced, copper-catalyzed C-N couplings

Abstract

Chapter 1 describes the development of three nickel-catalyzed asymmetric Negishi cross-couplings of secondary alkyl electrophiles via a stereoconvergent process. In Section 1.1, asymmetric Negishi arylations and alkenylations of [alpha]-bromonitriles with arylzinc and alkenylzinc reagents are achieved using a nickel/bis(oxazoline) catalyst. Section 1.2 describes stereoconvergent cross-couplings of secondary unactivated alkyl electrophiles, specifically, Negishi arylations and alkenylations of [alpha]-bromosulfonamides and abromosulfones with arylzinc reagents and alkenylzirconium reagents, respectively. Section 1.3 details progress toward asymmetric cross-couplings between [alpha]-haloboronate esters and alkylzinc reagents using a nickel/diamine catalyst. Chapter 2 describes the development of photoinduced, copper-catalyzed C-N couplings between N-heterocycles and aryl halides. In particular, a variety of N-heterocycles, such as indoles, benzimidazoles, imidazoles, and carbazoles, undergo Ullmann couplings under mild conditions (room temperature) with an inexpensive catalyst (Cul, without an added ligand).