A Ru-catalyzed direct oxidative coupling reaction of vinyl ketones was developed. It offers a straightforward and atom-economical protocol for synthesis of functionalized (E,E)-1,6-dioxo-2,4-diene derivatives in moderate to good yields with...
A divergent formal synthesis of polyhydroxylated macrocyclic
lactone (+)-aspicillin and polyene bioactive natural product β-parinaric
acid and the total synthesis of non-terpenoid metabolite isolaurepan
have been achieved using a ruthenium-catalyzed stereo- and chemoselective
oxidative coupling reaction of easily accessible vinyl ketones and
acrylates. The crucial transformation involves the efficient synthesis
and functionalization of stereodefined (E,E)-1,6-dioxo-2,4-dienes
using simple reaction protocols, which enabled straightforward access
to a diverse range of bioactive natural products.
An efficient and convergent first
total syntheses of (±)-japonicol
B and (−)-japonicol C have been completed. The notable points
of the synthetic route are Lewis-acid-catalyzed Friedel–Crafts
reaction for one pot C–C and C–O bond formations resulting
in construction of the tricyclic meroterpenoid skeleton, one pot Pd(OH)2/C-catalyzed isomerization/hydrogenation, and site selective sp
3 C–H oxidation.
Bio-inspired enantioselective total syntheses of (−)-viminalins A, B, H, I, and N, isolated from the Myrtaceae family, were accomplished in a convergent fashion in 5, 5, 1, 1, and 3 steps, respectively.
Ru-catalysed oxidative coupling of allylsilanes and allyl esters with activated olefins has been developed via isomerization followed by C(allyl)-H activation providing efficient access to stereodefined 1,3-dienes in excellent yields. Mild...
We have developed a highly stereospecific cyclization of aziridine silanols into 1′-amino-tetrahydrofurans. Our protocol of stirring a substrate with 10 mol % Sc (OTf) 3 and 1 equivalent of NaHCO 3 in CH 2 Cl 2 is mild and compatible with a range of activating aziridine N-substituents (including tosylates, mesylates, and carbamates) and functional groups on the alkyl chains (including substituted aryl rings, alkyl bromides, and alkyl ethers). In all cases examined, trans di-substituted aziridine silanols give products with an erythro configuration; conversely, cis disubstituted aziridine silanols give products with a threo configuration. While literature syntheses of 1′-amino-tetrahydrofurans exist, only one example, contemporaneous with our work, uses a similar cyclization for their construction. Control experiments demonstrate that, for this transformation, the silanol is not particularly privileged, and a variety of protecting groups on the alcohol (including other silicon protecting groups, benzyl ethers, and MOM ethers) are compatible with product formation.
A formal synthesis of FR252921, a potent macrocyclic immunosuppressive agent, and a six-step synthesis of vitamin A have been demonstrated. The application of a ruthenium-catalyzed step-economic and environmentally benign strategy for the highly stereo-and chemoselective construction of valuable polyene motifs of FR252921 and vitamin A highlights the syntheses. The key features for the synthesis FR252921 include preparation of the triene moiety followed by two consecutive peptide couplings of the three fragments. Letter pubs.acs.org/OrgLett
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