Advances in Metal-Catalyzed C–H Borylation and Multicomponent Allylic Substitution Reactions
multicomponent reactions , C-H activation , allylic substitution , Mizoroki-Heck reaction , iridium-catalyzed C-H borylation
Chapter one of this thesis describes the iridium-catalyzed ortho-selective C–H borylation reaction of tertiary benzamides. An iridium(I) complex paired with an electron-deficient phosphine ligand allows for efficient C–H activation and borylation using B2pin2. N,N-diethylbenzamides are challenging substrates for the reaction, however a variety of N,N-diisopropylbenzamides are well tolerated, affording the borylated products in generally high yields and good to excellent regioselectivities. This methodology acts as a complementary method to both Directed ortho Metalation (DoM) and a previously developed meta-selective borylation. We have demonstrated the utility of these boron-containing products by further cross-coupling reactions and DoM chemistry. Chapter two of this thesis describes our efforts towards a transition metal-catalyzed 3-component reaction, combining C–H activation and allylic substitution chemistry. Preliminary results were fraught with issues of compatibility of the required conditions for these two powerful reactions, and therefore a metal-catalyzed 3-component reaction using an aryl halide, diene, and nucleophile was explored as an alternative. Results indicate that this reaction is feasible using cyclic amine nucleophiles, generating aminated proucts containing a new stereogenic center. Attempts to use additional nucleophiles, as well as initial efforts to make the reaction proceed in an enantioselective fashion, will be described.