Double Radical Cyclization/β-Fragmentation of Acyclic ω-Yne Vinyl Sulfides. Synthesis of 3-Vinyldihydrothiophene and Dihydrothiopyran Derivatives. A New Example of a 5-endo-trig Radical Cyclization
Two efficient procedures involving tin hydride or thiophenol-mediated intramolecular homolytic substitution at the sulfur atom are reported. They lead to the generation of varied P(V)-centered radicals from the corresponding aryl or alkyne thiophosphorus substrates. The radical formed can be trapped by an olefin via an intermolecular addition, leading to the construction of C–P bonds. Thiophosphination
Gold- or Platinum-Catalyzed Synthesis of Sulfur Heterocycles: Access to Sulfur Ylides without Using Sacrificial Functionality
作者:Paul W. Davies、Sébastien J.-C. Albrecht
DOI:10.1002/anie.200904309
日期:2009.10.19
It′s no sacrifice: Alkynes have been used as direct precursors to sulfur ylides under gold or platinum π‐acid catalysis in an atom‐economic manner. An intramolecular redox reaction between an alkyne group with a tethered sulfoxide unit generates a sulfur ylide, which undergoes 2,3‐sigmatropicrearrangement. Acyclic substrates are cycloisomerized to afford functionalized dihydrothiophenones (see scheme)
Homolytic substitution at the sulfur atom of beta-(phenylsulfanyl)vinyl radicals, obtained by radicalreaction of benzenethiol with easily accessible alkyl 4-pentynyl sulfides, is a mild, effective, tin-free route for the generation of all types of alkylradicals. This protocol can be employed in reductive defunctionalizations as well as cyclizations onto both electron-rich and electron-poor C-C double
Site-specific introduction of gold-carbenoids by intermolecular oxidation of ynamides or ynol ethers
作者:Paul W. Davies、Alex Cremonesi、Nicolas Martin
DOI:10.1039/c0cc02736g
日期:——
Ynamides and ynol ethers undergo intermolecular gold-catalysed reaction with a nucleophilic oxidant to access metal-carbenoid reactivity patterns. A site-specific oxidation/1,2-insertion cascade is used for a general access to functionalised α,β-unsaturated carboxylic acid derivatives and vinylogous carbimates.
[EN] REVERSIBLE TERMINATORS FOR DNA SEQUENCING AND METHODS OF USING THE SAME<br/>[FR] TERMINATEURS RÉVERSIBLES POUR SÉQUENÇAGE D'ADN ET PROCÉDÉS D'UTILISATION CORRESPONDANTS
申请人:CENTRILLION TECH INC
公开号:WO2021067970A1
公开(公告)日:2021-04-08
The present disclosure provides methods of sequencing polynucleotides and compounds, compositions for sequencing of polynucleotides, and synthesis of such compositions. The chemical compounds include nucleotides and their analogs which possess a sugar moiety comprising a cleavable chemical group capping the 3'-OH group and a base, but without covalently bounded dye. The cleavable chemical group is reactive to form covalent bond(s) with a dye used to confirm the presence of the expected base-pairing. The cleavable chemical group capping the 3'OH group can be removed together with the covalently bounded dye. Furthermore, after the cleavable chemical group is cleaved, the free 3'-OH group can be active in continued elongation. Example chemical compounds according to the present disclosure are shown as Formulas (II) and (V).