Vnmrs 400

Chemical reagents and solvents, except for DNA solid phase synthesis, were purchased from commercial supplier (Aldrich or Wako or TCI) and used without further purification. Reagents for DNA solid phase synthesis were purchased from GlenResearch, except for FAM and Dabcyl amidite, which for ChemGenes. All the chemically modified DNA oligomers were synthesized on 1 μmol scale with an AppliedBiosystems 3400 DNA synthesizer. A standard program with 3′ CE (β-cyanoethyl) nucleotide phosphoramidites was used. All the staple DNAs for the DNA frame were purchased from Operon Biotechnology. Single-stranded M13mp18 viral DNA was purchased from New England Biolabs, Inc. Nuclear magnetic resonance spectra were recorded on a Varian VNMRS 400 or 600 MHz spectrometer. Mass spectra were recorded on a BrukerDaltonics MicroTOF-Q. Reverse-phase HPLC were performed on a Shimadzu Prominence HPLC system equipped with a Chemcobond 5-ODS-H C18 column (4.6 × 15 cm) using a SPD-M20A diode array detector at 254 nm. UV experiments were recorded on Jasco V-630BIO instrument equipped with a microcell holder. Fluorescence experiments were recorded on Jasco FP-8500 instrument equipped with a thermostatted cell holder.

Chemical structure of the purified compound was elucidated by analysis of its proton nuclear magnetic resonance (¹H-NMR) and carbon-13 (¹³C-NMR) spectra (Table 1). Nuclear magnetic resonance (NMR) spectra were taken on a Varian VNMRS 400 spectrometer with tetramethylsilane (TMS) as internal standard. Affinin was identified by comparing its spectroscopic constants with those reported in the literature [20 (link),21 (link)].

All reactions were carried out under anhydrous conditions in an argon atmosphere with dry, freshly distilled solvents. Analytical thin-layer chromatography was performed on SiO₂ (Merck silica gel 60 F₂₅₄), and the spots were located with 1% aqueous KMnO₄. Chromatography, referring to flash chromatography, was carried out on SiO₂ (SDS silica gel 60 ACC, 35–75 mm, 230–240 mesh ASTM). Drying of organic extracts during workup of reactions was performed over anhydrous MgSO₄ except where stated otherwise. Evaporation of solvent was accomplished with a rotatory evaporator. NMR spectra were recorded in CDCl₃ or MeOD on a Varian VNMRS 400 (Varian, Palo Alto, CA, USA). Chemical shifts of ¹H and ¹³C NMR spectra are reported in ppm downfield (δ) from Me₄Si. Electron-spray ionization mass spectra in positive mode (ESI-MS) data were recorded on a Bruker Esquire 3000 + spectrometer (Bruker Daltonics Inc., Billerica, MA, USA).

Experimental procedures and details, NMR spectra, and computational and crystallographic details can be found in the Supporting Information. In addition, NMR and computational data files can be obtained from the 4TU database under DOI: 10.4121/20015018.
Deposition Number(s) 2160732 (for 2) and CCDC 2160733 (for 5) contain the supplementary crystallographic data for this paper. These data are provided free of charge by the joint Cambridge Crystallographic Data Centre and Fachinformationszentrum Karlsruhe Access Structures service.
Procedure for the semi‐hydrogenation of internal alkynes: 0.60 mL of a stock solution of complex 3 (2.5 μmol/0.60 mL) in C₆D₆ was added to the alkyne substrate (50 μmol, 20 equiv). The solutions were then transferred to J. Young valved NMR tubes and mesitylene (internal standard, 3.0 μL) was added. The mixtures were degassed by three freeze‐pump‐thaw cycles and filled with H₂ (1 atm). The mixtures were placed in an oil bath at 25 °C (or 40 °C for some experiments) and the quantitative NMR spectra were collected after 24 h or 48 h (using an acquisition time of 5 sec and a relaxation time between scans set at 20 sec). Spectroscopic yields were determined with mesitylene as the internal standard. NMR data was recorded on an Agilent MRF 400 equipped with a OneNMR probe and Optima Tune system or a Varian VNMR−S‐400 equipped with a PFG probe at 298 K.