Exclusive 5-<i>exo-dig</i> Hydroarylation of <i>o</i>-Alkynyl Biaryls Proceeding via C−H Activation Pathway

Exclusive 5-exo-dig Hydroarylation of o-Alkynyl Biaryls Proceeding via C−H Activation Pathwa

Correction to Continuous-Flow Synthesis of Monoarylated Acetaldehydes Using Aryldiazonium Salts

Correction to Continuous-Flow Synthesis of Monoarylated Acetaldehydes Using Aryldiazonium Salt

Continuous-Flow Synthesis of Monoarylated Acetaldehydes Using Aryldiazonium Salts

Anilines and ethyl vinyl ether can be used as precursors for a process that is the synthetic equivalent of the α-arylation of acetaldehyde enolate. The reaction manifests a high level of functional group compatibility, allowing the ready preparation of a number of synthetically valuable compounds

Dual Role of Alkynyl Halides in One-Step Synthesis of Alkynyl Epoxides

Dual Role of Alkynyl Halides in One-Step Synthesis of Alkynyl Epoxide

Direct Pd-Catalyzed Arylation of 1,2,3-Triazoles^†

A highly efficient method for the synthesis of multisubstituted 1,2,3-triazoles via a direct Pd-catalyzed C-5 arylation has been developed

PyDipSi: A General and Easily Modifiable/Traceless Si-Tethered Directing Group for C−H Acyloxylation of Arenes

PyDipSi: A General and Easily Modifiable/Traceless Si-Tethered Directing Group for C−H Acyloxylation of Arene

Rhodium-Catalyzed Transannulation of 1,2,3-Triazoles with Nitriles

Rhodium-Catalyzed Transannulation of 1,2,3-Triazoles with Nitrile

Liposomal Spherical Nucleic Acids

A novel class of metal-free spherical nucleic acid nanostructures was synthesized from readily available starting components. These particles consist of 30 nm liposomal cores, composed of an FDA-approved 1,2-dioleoyl-<i>sn</i>-glycero-3-phospho­choline (DOPC) lipid monomer. The surface of the liposomes was functionalized with DNA strands modified with a toco­pherol tail that intercalates into the phospho­lipid layer of the liposomal core via hydrophobic interactions. The spherical nucleic acid architecture not only stabilizes these constructs but also facilitates cellular internalization and gene regulation in SKOV-3 cells

Modification of Cysteine-Substituted Antibodies Using Enzymatic Oxidative Coupling Reactions

Cysteines are routinely used as site-specific handles to synthesize antibody–drug conjugates for targeted immunotherapy applications. Michael additions between thiols and maleimides are some of the most common methods for modifying cysteines, but these functional groups can be difficult to prepare on scale, and the resulting linkages have been shown to be reversible under some physiological conditions. Here, we show that the enzyme tyrosinase, which oxidizes conveniently accessed phenols to afford reactive ortho-quinone intermediates, can be used to attach phenolic cargo to cysteines engineered on antibody surfaces. The resulting linkages between the thiols and ortho-quinones are shown to be more resistant than maleimides to reversion under physiological conditions. Using this approach, we construct antibody conjugates bearing cytotoxic payloads, which exhibit targeted cell killing, and further demonstrate this method for the attachment of a variety of cargo to antibodies, including fluorophores and oligonucleotides

Tip-Directed Synthesis of Multimetallic Nanoparticles

Alloy nanoparticles are important in many fields, including catalysis, plasmonics, and electronics, due to the chemical and physical properties that arise from the interactions between their components. Typically, alloy nanoparticles are made by solution-based synthesis; however, scanning-probe-based methods offer the ability to make and position such structures on surfaces with nanometer-scale resolution. In particular, scanning probe block copolymer lithography (SPBCL), which combines elements of block copolymer lithography with scanning probe techniques, allows one to synthesize nanoparticles with control over particle diameter in the 2–50 nm range. Thus far, single-element structures have been studied in detail, but, in principle, one could make a wide variety of multicomponent systems by controlling the composition of the polymer ink, polymer feature size, and metal precursor concentrations. Indeed, it is possible to use this approach to synthesize alloy nanoparticles comprised of combinations of Au, Ag, Pd, Ni, Co, and Pt. Here, such structures have been made with diameters deliberately tailored in the 10–20 nm range and characterized by STEM and EDS for structural and elemental composition. The catalytic activity of one class of AuPd alloy nanoparticles made via this method was evaluated with respect to the reduction of 4-nitrophenol with NaBH₄. In addition to being the first catalytic studies of particles made by SPBCL, these proof-of-concept experiments demonstrate the potential for SPBCL as a new method for studying the fundamental science and potential applications of alloy nanoparticles in areas such as heterogeneous catalysis