TiCl4-promoted aldol condensations of S-4-chlorophenyl thioesters with enals or dienals led to the production of dienyl or trienyl thioesters in good yields. Due to good crystallinity, products with high E/Z ratios were obtained by simple filtration in many cases. Reduction of the thioester moiety by DIBAL-H afforded the corresponding unsaturated aldehydes while suppressing the E/Z-isomerization and
Diversity‐oriented biosynthesis of a library of antimycin‐like compounds (380 altogether) was accomplished by using multiplex combinatorial biosynthesis. The core strategy depends on the use of combinatorial chemistry at different biosynthetic stages. This approach is applicable for the diversification of polyketides, nonribosomal peptides, and the hybrids that share a similar biosynthetic logic.
Nickel-catalyzed, highly diastereoselective annulations between activated allenes and 2-acetylarylboronic acid or 2-formylarylboronic acids are reported. No ligand for nickel is required, and the reactions proceed efficiently at room temperature to give a broad range of substituted 3-methyleneindan-1-ols. Preliminary results of an enantioselective variant are also described.
Post-synthetic functionalization of tryptophan protected peptide sequences through indole (C-2) photocatalytic alkylation
作者:Rafaely N. Lima、José A. C. Delgado、Darlon I. Bernardi、Roberto G. S. Berlinck、Nikolaos Kaplaneris、Lutz Ackermann、Márcio W. Paixão
DOI:10.1039/d1cc01822a
日期:——
report a selective, mild, and efficient C–H functionalization of tryptophan and tryptophan-containing peptides with activated α-bromo-carbonyl compounds under visible-light irradiation. The protocol efficiency is outlined by the wide substrate scope and excellent tolerance of sensitive functional groups present in the amino acid sidechains. The method can be successfully extended to access pharmaco-peptide
Direct carbon–carbon bond formation via soft enolization: aldol addition of α-halogenated thioesters
作者:Julianne M. Yost、Rachel J. Alfie、Emily M. Tarsis、Insun Chong、Don M. Coltart
DOI:10.1039/c0cc02345k
日期:——
α-Halo thioesters undergo soft enolization and syn-selective direct aldol addition to aldehydes in the presence of MgBr2·OEt2 and i-Pr2NEt to produce α-halo-β-hydroxy thioesters.