Additions of Thiols to 7-Vinyl-7-deazaadenine Nucleosides and Nucleotides. Synthesis of Hydrophobic Derivatives of 2′-Deoxyadenosine, dATP and DNA

Abstract

Additions of alkyl- or arylthiols to 7-vinyl-7-deaza-2'-deoxyadenosine gave a series of 7-[2-(alkyl- or arylsulfanyl)ethyl]-7-deaza-2'-deoxyadenosines in 45-85% yields. The nucleosides were converted to 5'-O-mono-(dAMP) or triphosphates (dATP) by phosphorylation. The modified triphosphates were also prepared by thiol addition to 7-vinyl-7-deaza-dATP. The triphosphates dATP were good substrates for DNA polymerases useful in the enzymatic synthesis of base-modified oligonucleotides (ONs) or DNA containing flexibly linked hydrophobic substituents in the major groove. Primer extension was used for the synthesis of ONs with one or several modifications, PCR was used for the synthesis of heavily modified DNA, whereas terminal deoxynucleotidyl transferase was used for a single-nucleotide labeling of the 3'-end.

Terminal Deoxynucleotidyl Transferase in the Synthesis and Modification of Nucleic Acids

“…These favorable properties can then be exploited in various bioanalytical assays, including the monitoring of DNA hybridization and the detection of DNA–protein interactions . More recently, the same group has reported the use of vinyl‐modified dNTPs ( 7 in Scheme ) for the introduction of functional groups into DNA through the thiol‐ene reaction for the subsequent labeling of DNA . Ferrocene is another highly active redox label that has been introduced into DNA by the TdT .…”

Synthesis of Dihydroxyalkynyl and Dihydroxyalkyl Nucleotides as Building Blocks or Precursors for Introduction of Diol or Aldehyde Groups to DNA for Bioconjugations

“…We developed an efficient and straightforward synthesis of diol‐modified dNTPs through direct aqueous Sonogashira coupling of halogenated dNTPs with ( S )‐but‐3‐yne‐1,2‐diol. For the very first time, we report here on a successful catalytic hydrogenation of labile dihydroxyalkynyl dN DHY TP s to dihydroxyalkyl dN DHA TP s. This method is an important addition to the portfolio of synthetic methods available for modification of fragile nucleoside triphosphates because so far introduction of an sp 3 ‐linked alkyl substituents directly to dNTPs was only reported using thiol‐ene additions . The oxidative cleavage of dihydroxyalkynyl nucleotides by periodate gave mixtures of products, whereas the cleavage of dihydroxyalkyl deazaadenine nucleotide dA DHA TP led to unexpected formation of undesired cyclic aminal dA AL TP .…”

Thiol−Ene Reaction: Synthetic Aspects and Mechanistic Studies of an Anti‐Markovnikov‐Selective Hydrothiolation of Olefins

“…In the same year, Hocek and coworkers employed thiol‐ene reaction for synthesis of 2′‐deoxyadenosine, dATP and DNA 101 using thiols 100 and 7‐Vinyl‐7‐deazaadenine nucleosides and nucleotides 99 (Scheme ) . The additions of alkyl‐ or aryl thiols to 7‐vinyl‐7‐deaza2′‐deoxyadenosine provided a series of 7‐[2‐(alkyl‐ or aryl sulfanyl) ethyl]‐7‐deaza‐2′‐deoxy adenosines in good yields.…”