A flurry of recent research has centered on harnessing the power of nickel catalysis in organic synthesis. These efforts have been bolstered by contemporaneous development of well-defined nickel (pre)catalysts with diverse structure and reactivity. In this report, we present ten different bench-stable, 18-electron, formally zero-valent nickel-olefin complexes that are competent pre-catalysts in various reactions.
View Article and Find Full Text PDFAn asymmetric 1,2-dicarbofunctionalization of unactivated alkenes with aryl iodides and aryl/alkenylboronic esters under nickel/bioxazoline catalysis is disclosed. A wide array of aryl and alkenyl nucleophiles are tolerated, furnishing the products in good yield and with high enantioselectivity. In addition to terminal alkenes, 1,2-disubstituted internal alkenes participate in the reaction, establishing two contiguous stereocenters with high diastereoselectivity and moderate enantioselectivity.
View Article and Find Full Text PDFAn operationally simple, scalable, and chemoselective method for the direct phosphorylation of alcohols using a P(V)-approach based on the Ψ-reagent platform is disclosed. The method features a broad substrate scope of utility in both simple and complex settings and provides access to valuable phosphorylated alcohols that would be otherwise difficult to obtain.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
March 2021
Gram-positive bacteria assemble a multilayered cell wall that provides tensile strength to the cell. The cell wall is composed of glycan strands cross-linked by nonribosomally synthesized peptide stems. Herein, we modify the peptide stems of the Gram-positive bacterium with noncanonical electrophilic d-amino acids, which when in proximity to adjacent stem peptides form novel covalent 5,3-cross-links.
View Article and Find Full Text PDFControlled site-specific bioconjugation through chemical methods to native DNA remains an unanswered challenge. Herein, we report a simple solution to achieve this conjugation through the tactical combination of two recently developed technologies: one for the manipulation of DNA in organic media and another for the chemoselective labeling of alcohols. Reversible adsorption of solid support (RASS) is employed to immobilize DNA and facilitate its transfer into dry acetonitrile.
View Article and Find Full Text PDFEnantioenriched -aminoboronic acids play a unique role in medicinal chemistry and have emerged as privileged pharmacophores in proteasome inhibitors. Additionally, they represent synthetically useful chiral building blocks in organic synthesis. Recently, CuH-catalyzed asymmetric alkene hydrofunctionalization has become a powerful tool to construct stereogenic carbon centers.
View Article and Find Full Text PDFThe emerging use of covalent ligands as chemical probes and drugs would benefit from an expanded repertoire of cysteine-reactive electrophiles for efficient and diverse targeting of the proteome. Here we use the endogenous electrophile sensor of mammalian cells, the KEAP1-NRF2 pathway, to discover cysteine-reactive electrophilic fragments from a reporter-based screen for NRF2 activation. This strategy identified a series of 2-sulfonylpyridines that selectively react with biological thiols via nucleophilic aromatic substitution (SAr).
View Article and Find Full Text PDFDNA encoded libraries (DEL) have shown promise as a valuable technology for democratizing the hit discovery process. Although DEL provides relatively inexpensive access to libraries of unprecedented size, their production has been hampered by the idiosyncratic needs of the encoding DNA tag relegating DEL compatible chemistry to dilute aqueous environments. Recently reversible adsorption to solid support (RASS) has been demonstrated as a promising method to expand DEL reactivity using standard organic synthesis protocols.
View Article and Find Full Text PDFDNA Encoded Libraries have proven immensely powerful tools for lead identification. The ability to screen billions of compounds at once has spurred increasing interest in DEL development and utilization. Although DEL provides access to libraries of unprecedented size and diversity, the idiosyncratic and hydrophilic nature of the DNA tag severely limits the scope of applicable chemistries.
View Article and Find Full Text PDFHistorically accessed through two-electron, anionic chemistry, ketones, alcohols, and amines are of foundational importance to the practice of organic synthesis. After placing this work in proper historical context, this Article reports the development, full scope, and a mechanistic picture for a strikingly different way of forging such functional groups. Thus, carboxylic acids, once converted to redox-active esters (RAEs), can be utilized as formally nucleophilic coupling partners with other carboxylic derivatives (to produce ketones), imines (to produce benzylic amines), or aldehydes (to produce alcohols).
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