Tags: Organic Seminar

The Manetsch laboratory focuses on synthetic chemistry and the development of LC/MS-guided medicinal chemistry approaches for the development of anti-infective agents. The first half of the seminar focuses on the streptothricin natural products class, while kinetic Target-Guided Synthesis (kTGS) is the topic of the second half of the seminar. Streptothricins are highly active against gram-positive and gram-negative ESKAPE pathogens. Common…
The herquline family of natural products were originally isolated from penicillium herquei in 1979 by the Ōmura group (see figure below). These strained macrocyclic alkaloids all contain multiple stereocenters, and an unsymmetrically substituted piperazine. Herqulines B and C feature two β,γ-unsaturated cyclohexenones, while herquline A bears an additional pyrrolidine. In the intervening years since their isolation, numerous failed synthetic…
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…