Tags: Organic Seminar

The use of metal–hydrogen atom transfer (MHAT) for olefin hydrofunctionalization has received great attention over the last 20 years, primarily due to its enhanced chemoselectivity and regioselectivity.[1] The Giese reaction, or the addition of a carbon-centered radical into an electron-deficient alkene, is well-known and has been commonly employed for C–C bond formation over the last 40 years.[2] More recently, the Baran group coupled these two…
Photoredox catalysis has emerged as an integral fraction of modern organic methodology.[1] Since the early 2000’s there has been a renewed interest in photochemistry, with photoredox catalysis utilizing visible light becoming a rapidly expanding field. Various transition-metal complexes have been developed and proven efficient photocatalysts; however, the two most commonly employed metals in these systems are the incredibly expensive, rare-earth…
Cycloisomerizations of 1,n-enynes catalyzed by electrophilic p-acid metal complexes provide a powerful method of carbon–carbon bond formation, and a unique platform for studying reactivity and mechanism.1  Our previous report on the total synthesis of (±)-gelsenicine took advantage of a cycloisomerization/rearrangement strategy to access the central bridging bicyclic structure of the compound.2  Continuing our interest in the…
Automated transiton state (TS) structure computations for a recently reported Pd-catalysed conjugated addition of arylboronic acids to 2-substituted chromones (Chem Sci, 2020, 11, 4602) reveal unexpected conformations of the key stereodifferentiating benzyl group on the pyridine-dihydroisoquinoline (PyDHIQ) ligand. Detailed analysis shows that stereoselectivity is determined primarily by favorable non-covalent contacts between this benzyl group…
Conventional cross-coupling reactions typically involve the union of a nucleophilic and electrophilic coupling partner. In contrast, reductive (or cross-electrophile) coupling has recently emerged as an alternative approach in which two electrophilic partners can be coupled together. However, achieving cross-selectivity is an ongoing challenge for it necessitates chemoselective activation of one electrophile over the other. Three recently…