This paper describes our efforts to design a Pd-catalyzed asymmetric prenylation of 3-substituted oxindoles that affords access to both the linear and reverse-prenylated products. Both 3-alkyl- and 3-aryloxindoles performed well under our optimized reaction conditions. The regiodivergent alkylation of monoterpene-derived electrophiles using this methodology was also investigated. The utility of this methodology in natural product synthesis was demonstrated through the efficient total syntheses of four Flustra alkaloids, which also allowed the absolute stereochemistry of the prenylated oxindole products to be assigned. Surprisingly, the same enantiomer of ligand produced linear and branched regioisomers of opposite chirality.
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http://dx.doi.org/10.1002/chem.201605810 | DOI Listing |
Angew Chem Int Ed Engl
December 2024
Centre for Analysis and Synthesis, Department of Chemistry, Lund University, SE-221 00, Lund, Sweden.
Thiosilvatins are a family of biologically active sulfenylated diketopiperazine natural products. The first members were reported over 40 years ago, but total synthesis of a thiosilvatin has remained elusive. Here, we describe the first, collective, synthesis of the parent epidithiodiketopiperazine (-)-dithiosilvatin and ten related thiosilvatins.
View Article and Find Full Text PDFCommun Biol
November 2023
McGovern Medical School, University of Texas Health Science Center at Houston, Department of Integrative Biology and Pharmacology, 6431 Fannin St., Houston, TX, 77030, USA.
We studied diverse prenylated intrinsically disordered regions (PIDRs) of Ras and Rho family small GTPases using long timescale atomistic molecular dynamics simulations in an asymmetric model membrane of phosphatidylcholine (PC) and phosphatidylserine (PS) lipids. Here we show that conformational plasticity is a key determinant of lipid sorting by polybasic PIDRs and provide evidence for lipid sorting based on both headgroup and acyl chain structures. We further show that conformational ensemble-based lipid recognition is generalizable to all polybasic PIDRs, and that the sequence outside the polybasic domain (PBD) modulates the conformational plasticity, bilayer adsorption, and interactions of PIDRs with membrane lipids.
View Article and Find Full Text PDFOrg Lett
September 2023
Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, 22 Xinong Road, Yangling, 712100 Shaanxi, China.
A catalytic asymmetric nucleophilic reverse prenylation of indol-2-ones generated from 3-bromooxindoles with prenyltributylstannane promoted by Ni(II)/chiral -dioxide was developed. This reaction provides facile access to C3 reverse-prenylated oxindoles in good to excellent enantioselectivities, which enabled the asymmetric synthesis of debromoflustramine A in five steps.
View Article and Find Full Text PDFWe studied diverse prenylated intrinsically disordered regions (PIDRs) of Ras and Rho family small GTPases using long timescale atomistic molecular dynamics simulations in an asymmetric model membrane of phosphatidylcholine (PC) and phosphatidylserine (PS) lipids. We show that conformational plasticity is a key determinant of lipid sorting by polybasic PIDRs and provide evidence for lipid sorting based on both headgroup and acyl chain structures. We further show that conformational ensemble-based lipid recognition is generalizable to all polybasic PIDRs, and that the sequence outside the polybasic domain (PBD) modulates the conformational plasticity, bilayer adsorption, and interactions of PIDRs with membrane lipids.
View Article and Find Full Text PDFJ Org Chem
June 2023
Organic Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
We report an improved synthetic protocol for hydroxy methyl-derived polysubstituted furans employing Bi(III)-catalyzed dehydrative cycloisomerization of α-hydroxy oxetanyl ketones. This procedure provides rapid access (within 5 min) to highly substituted furans with exceptional functional group diversity, excellent yields, generality, scalability, and operationally simple reaction conditions. Further, it demonstrated the utility of this method in the first enantioselective total synthesis of furyl-hydroquinone-derived biologically potent natural products shikonofurans J, D, E, and C in seven linear steps, starting from readily available building blocks of 2,5-dihydroxy acetophenone and 3-oxetanone employing chiral-phosphoric acid (TRIP)-catalyzed asymmetric prenylation as a key step to induce the chirality.
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