Trivalent phosphoramidite derivatives could be readily converted by reacting with 1-hydroxy-7-azabenzotriazole to phosphotriester intermediates; these intermediates reacted smoothly with phosphorylated compounds to give pyrophosphate derivatives. This new phosphorylation approach enabled a facile and rapid synthesis of 5'-adenylated DNA oligomers (A(5')ppDNA) on resins using a silyl-type linker. Our new approach could be applied to the synthesis of a 2'-OMe-RNA oligomer containing the 5'-terminal 2,2,7-trimethylguanosine cap structure.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ol2026075 | DOI Listing |
J Am Chem Soc
January 2025
New Cornerstone Science Laboratory, State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China.
The asymmetric Tsuji-Trost reaction has been extensively studied due to its importance in establishing stereogenic centers, often adjacent to an -olefin moiety in organic molecules. The generally preferential formation of chiral -olefin products is believed to result from the thermodynamically more stable -π-allylpalladium intermediate. The rapid associative π-σ-π isomerization makes it challenging to synthesize chiral -olefin products via the transient -π-allylpalladium intermediate.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
We report a copper-catalyzed regio-, diastereo-, and enantioselective allylic alkylation of allyl bromides using 1,1-diborylalkanes as prochiral nucleophiles. This methodology employs copper(I) bromide as a catalyst, an ()-BINOL-derived phosphoramidite as a ligand, and lithium benzoate as a crucial additive. The reaction affords enantioenriched homoallylic boronic esters possessing vicinal stereocenters in good yields and high diastereo- and enantioselectivity.
View Article and Find Full Text PDFNat Commun
December 2024
Key Laboratory of Precision and Intelligent Chemistry and Department of Chemistry, University of Science and Technology of China, 230026, Hefei, P. R. China.
Even though tuning electronic effect of chiral ligands has proven to be a promising method for designing efficient catalysts, the potential to achieve highly selective reactions by this strategy remains largely unexplored. Here, we report a palladium-catalyzed enantioselective ring-closing aminoalkylative amination of aminoenynes enabled by rationally tuning the remote electronic property of 1,1'-binaphthol-derived phosphoramidites. With a tailored 6,6'-CN-substituted 1,1'-binaphthol-derived phosphoramidite as a ligand, a broad range of aromatic amines are compatible with this reaction, allowing the efficient synthesis of a series of enantioenriched exocyclic allenylamines bearing saturated N-heterocycles with up to >99% enantiomeric excess.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany.
A VAPOL-derived phosphoramidite ligand is uniquely effective at reverting the regiochemical course of nickel-catalyzed reactions of aldehydes with carbamate-protected 5-amino-2,4-pentadienoates as "push/pull" dienes; the ensuing carbonyl α-amino-homoallylation reaction affords -configured -aminoalcohol derivatives in good yields with high optical purity. The reductive coupling is conveniently performed with a bench-stable Ni(0) precatalyst and EtB as the promoter.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Kolkata 700 032, India.
Phosphorodiamidate Morpholino Oligonucleotides (PMOs) have been well established in the milieu of FDA-approved oligonucleotide-based drugs in the past decade. Given their relevance in antisense therapeutics, a DNA/RNA synthesizer-compatible modular synthesis protocol of PMOs is long awaited to explore next-generation PMO chimeras with other therapeutically proven oligonucleotide backbones. Herein, we demonstrate a streamlined 5' → 3'phosphoramidite approach for the synthesis of PMOs using -butyl-protected 5'-morpholino phosphoramidites, which were synthesized from 5'-OH morpholino monomers derived from commercially available ribonucleosides.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!