Vario micro cube instrument

Commercially available reagent-grade chemicals were used as received without any further purification unless mentioned. IR spectra were recorded on a FTS165 Bio-Rad FTIR spectrometer by using KBr pellets in the range 4000–400 cm⁻¹. Elemental analysis (C, H and N) was carried out using an Elementar Vario Micro Cube instrument at the Elemental Analysis Lab, CMMAC, Department of Chemistry, National University of Singapore. Thermogravimetric analysis (TGA) was performed under N₂ atmosphere with a heating rate of 5°C min⁻¹ on a SDT 2960 Thermal analyzer. NMR spectra were recorded on a 300 MHz Bruker Avance 300 FT-NMR spectrometer by calibrating the residual solvent as the reference in DMSO-d₆ solution. The powder X-ray diffraction (PXRD) patterns were recorded on a Siemens D5005 diffractometer with graphite monochromated Cu Kα radiation (λ = 1.54056 Å) at 298 K.

All manipulations were performed under a dinitrogen atmosphere using anhydrous solvents. [Alq₃] [62 (link),63 (link)] and HqNO [47 (link)] were synthesized according to the literature. Anhydrous [Ln(hfac)₃] species (Ln³⁺ = Eu³⁺, Gd³⁺ and Er³⁺) were obtained by dehydration of the corresponding dihydrate complex [Ln(hfac)₃(H₂O)₂] according to the procedure reported in the literature [64 (link)]. [Al(O^tBu)₃] was purchased from Sigma Aldrich. ATR-IR spectra on solid samples were recorded with a Perkin–Elmer ‘‘Spectrum One’’ spectrometer, equipped with an ATR accessory. ¹H NMR spectra were recorded with a Bruker “Avance DRX400” spectrometer. Chemical shifts were measured in ppm (δ) from TMS using residual solvent peaks. Elemental analyses (C, H and N) were performed using an Elementar “vario MICRO cube” instrument at Dipartimento di Chimica e Chimica Industriale, Università di Pisa.

Reactants and solvents were purchased
from Alfa Aesar, Merck, Strem, or TCI Chemicals and were of the highest
purity available. Diruthenacyclopentenone complex 1(36 (link)) and 3-ethynylphenyl 2-acetoxybenzoate^{38 (link),39 (link)} were prepared according to the literature. Reactions were conducted
under a N₂ atmosphere using standard Schlenk techniques.
Products were stored in air once isolated. Dichloromethane and tetrahydrofuran
were dried with the solvent purification system mBraun MB SPS5, while
acetonitrile was distilled from CaH₂. IR spectra of solutions
were recorded by using a CaF₂ liquid transmission cell
(2300–1500 cm^–1) on a PerkinElmer Spectrum
100 FT-IR spectrometer. IR spectra were processed with Spectragryph
software.^{80 1}H and ¹³C NMR spectra were recorded on a Jeol JNM-ECZ500R instrument equipped
with a Royal HFX Broadband probe at 298 K, unless otherwise specified.
Chemical shifts (expressed in parts per million) are referenced to
the residual solvent peaks.^{81 (link)} NMR spectra
were assigned with the assistance of ¹H–¹³C (gs-HSQC and gs-HMBC) correlation
experiments.^{82 (link)} NMR signals due to secondary
isomeric forms (where it is possible to detect them) are italicized.
Elemental analyses were performed on a Vario MICRO cube instrument
(Elementar).

Vancomycin hydrochloride was a gift from TEVA Pharmaceutical Industries Ltd. (Debrecen, Hungary). Vancomycin aglycone hexapeptide, trifluoromethanesulfonyl azide, compounds 4 and 5 were prepared as described elsewhere [24 (link),30 (link)]. TLC was performed on Kieselgel 60 F₂₅₄ (Merck) with detection either by immersing into ammonium molybdate-sulfuric acid solution followed by heating or by using Pauly’s reagent for detection. Flash column chromatography was performed using Silica gel 60 (Merck 0.040-0.063 mm) and Silica gel 60 silanized (0.063–0.200 mm). The ¹H NMR (500MHz, 400 MHz) ¹³C NMR (125 MHz, 100 MHz) and 2D NMR spectra were recorded with a Bruker DRX-400 and Bruker Avance II 500 spectrometers at 300K. Chemical shifts are referenced to Me₄Si and to the solvent residual signals. MALDI-TOF MS analysis of the compounds was carried out in the positive reflectron mode using a BIFLEX III mass spectrometer (Bruker, Bremen, Germany) equipped with delayed-ion extraction. 2,5-Dihydroxybenzoic acid (DHB) was used as matrix and CF₃COONa as cationizing agent in DMF. Elemental analysis (C, H, N, S) was performed on an Elementar Vario MicroCube instrument.