Site-Selective Unactivated Aliphatic C–H Functionalization as a Strategy for Molecular Diversification

I. Strategies for Intermolecular Functionalization of Unactivated Aliphatic C–H Bonds Aliphatic carbon–hydrogen (C–H) bonds are omnipresent in organic compounds, and strategies for their selective functionalization offer unique abilities in organic synthesis. Recent developments in the field of unactivated aliphatic C–H functionalization are described, and the advantages and limitations associated with them are discussed. II. Intermolecular Aliphatic C–H Xanthylation as a Strategy for Small Molecule Diversification The development of a site-selective aliphatic C–H xanthylation using an N- xanthylamide reagent is detailed. The alkyl xanthate products are converted into a wide array of functionality, highlighting the utility as a strategy for two-step C–H diversification. III. C–H Xanthylation as a Strategy for Polyolefin Functionalization and Diversification The application of the previously described aliphatic C–H xanthylation to polyolefins is shown. High levels of polymer functionalization are observed without the need for excess N-xanthylamide reagent, and problematic chain scission does not occur. The strategy is also amenable to the functionalization of high molecular weight commodity polyolefins. IV. Development of an Organic Photoredox-Catalyzed Strategy for Modular Aliphatic C–H Functionalization A modular unactivated aliphatic C–H functionalization strategy using photoredox catalysis is presented. The one-step conversion of C–H to C–N, C–F, C–Br, C–Cl, C–S, and C–C bonds is shown, and mechanistic studies suggest the intermediacy of an oxygen- centered radical. Preliminary results toward polyolefin functionalization are also discussed. V. Quaternary Center Construction via Coupling of Acyl Xanthates with Unactivated Alkenes The construction of quaternary centers from the addition of tertiary acyl xanthates to unactivated olefins is described. A wide variety of functionality is compatible with the transformation, and the subsequent reactivity of alkyl xanthate products allows for the products of net carbodifunctionalization reactions to be accessed.Doctor of Philosoph