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A combination of weakly coordinating auxiliaries and ligand acceleration allows for the development of both ortho- and meta-selective C–H olefination of phenol derivatives. These reactions demonstrate the feasibility of directing C–H functionalizations when functional groups are distal to target C–H bonds. The meta-C–H functionalization of electron-rich phenol derivatives is unprecedented and orthogonal to previous electrophilic substitution of phenols in terms of regioselectivity. These methods are also applied to functionalize α-phenoxyacetic acids, a fibrate class of drug scaffolds.

Modern drug discovery is contingent on identifying lead compounds and rapidly synthesizing analogues. The use of a common pharmacophore to direct multiple and divergent C-H functionalizations of lead compounds is a particularly attractive approach. Herein, we demonstrate the viability of late-stage diversification through the divergent C-H functionalization of sulfonamides, an important class of pharmacophores found in nearly 200 drugs currently on the market, including the non-steroidal anti-inflammatory blockbuster drug celecoxib. We developed a set of six categorically different sulfonamide C-H functionalization reactions (olefination, arylation, alkylation, halogenation, carboxylation, and carbonylation), each representing a distinct handle for further diversification to reach a large number of analogues. We then performed late-stage, site-selective diversification of a sulfonamide drug candidate containing multiple potentially reactive C-H bonds to synthesize directly novel celecoxib analogues as potential cyclooxygenase-II (COX-2)-specific inhibitors. Together with other recently developed practical directing groups, such as CONHOMe and CONHC(6)F(5), sulfonamide directing groups demonstrate that the auxiliary approach established in asymmetric catalysis can be equally effective in developing broadly useful C-H activation reactions.

The molecular design, chemical synthesis and biological evaluation of two distinct series of platensimycin analogs with varying degrees of complexity are described. The first series of compounds (analog series I: 6, 15–18, Figure 3) probes the biological importance of the benzoic acid subunit of the molecule, whilst the second series (analog series II: 2, 3, 9–14) explores the tetracyclic cage domain. The biological data obtained reveal that while the substituted benzoic acid domain of platensimycin is a highly conserved structural motif within the active compounds with strict functional group requirements, the cage domain of the molecule can tolerate considerable structural modifications without losing biological action. These findings refine our present understanding of the platensimycin pharmacophore and establish certain structure activity relationships (SARs) from which the next generation of designed analogs of this new antibiotic may emerge.

The chemical synthesis and biological evaluation of carbaplatensimycin, the carbon analogue of the recently reported antibiotic platensimycin has been accomplished. Carbaplatensimycin exhibited similar potency to the natural product as an antibacterial agent against a variety of strains, including methicilin- and vancomycin-resistant bacteria.