Selenium Catalyzed C-N bond formation

Abstract

Carbon-nitrogen bonds are an ubiquitous structural motif in natural products, biologicallyactive compounds, and organic materials. Our ability to design molecules that address modern problems requires an array of methods that allow us access to a myriad of carbon- nitrogen bonds. Herein, the development of two selenium catalyzed carbon-nitrogen bond forming reactions are described which add to the pantheon of methods to make this struc- tural motif; the propagylic C-H amination of alkynes and the regioselective C-H allylic amination of heteroatom substituted alkenes. The propagylic C-H amination of alkynes generated propargyl amines in good to excel- lent yields. The reaction functionalizes a wide variety of unactivated alkynes with a broad functioal group tolerance. The regiochemical trends of C-H amination of internal alkynes were explored and a mechanistic model was developed to predict the reactivity of different types of propargyl C-H bonds. kinetic isotope labeling experiments were carried out in conjunction to support our mechanistic model. The regioselective C-H allylic amination of heteroatom substituted alkenes generates allylic amines from a wide variety of enolate derivatives and alkenyl halides in good yields. The reaction is stereoconvergent to the Z-alkene and gives a single regio isomer. We demon- strate how thermodynamic and kinetic enolization correlates to subsequent regiochemical control of C-H amination. Additionally we measured relative reaction rates of differing alkenyl substiutents to compare different functional group reactivities.