Deuterated solvents

All experiments were
carried out under inert conditions using standard Schlenk and glovebox
techniques (argon atmosphere). All solvents were purchased in HPLC
quality (Sigma-Aldrich) and dried using an MBRAUN Solvent Purification
System. THF, HMDSO, and toluene were additionally dried over an Na/K-alloy.
Deuterated solvents were obtained from Eurisotop GmbH and dried over
an Na/K-alloy (C₆D₆, THF-d₈, Tol-d₈), distilled by trap-to-trap transfer in vacuo and degassed by three freeze–pump–thaw cycles, respectively. Silica gel 60 silanized was purchased from
Merck KGaA and heated at 120 °C in vacuo for
5 days prior to use. Purification of CO gas (Air Liquide) was obtained
by passing the gas through a steel coil cooled to −78 °C. ¹³CO (Eurisotop GmbH, 99.30%) and ¹⁵N₂ (Sigma-Aldrich, 98% ¹⁵N) were used without further purification. N-Chlorosuccinimide (NCS) was sublimed prior to use. Me₃SiNCO and Me₃SiCl were distilled and degassed. t-Butylisocyanide (Sigma-Aldrich) and 4-methoxyphenylisocyanide
(Sigma-Aldrich) were used as purchased without further purification,
whereas [(N₂){WCl(PNP)}₂] (1) was
synthesized according to published procedures.^{31 (link)}

All reactions were performed in oven-dried glassware under normal atmosphere, unless otherwise noted. All reagents and solvents were purchased from Fluorochem, TCI, or Merck and used without any further purification. Where specified, reactions were monitored via thin-layer chromatography (TLC) on POLYGRAM^® Xtra Sil G/UV254 (0.2 mm layer thickness; Macherey-Nagel); spots were observed under a UV lamp at 254 or 365 nm. Gravimetric column chromatography was performed using silica gel (60 Å, particles size: 0.63–0.2 mm) as stationary phase. ¹H, ^13c, ¹⁹F, and ¹¹B NMR spectra were acquired on a Bruker AVANCE I 400 instrument at 400.13, 100.61, 376.5, and 128.38 MHz, respectively, and are referenced using residual non-deuterated solvents (CHCl₃ 7.26 ppm in CDCl₃, DMSO 2.50 ppm in d₆-DMSO); deuterated solvents were purchased from Eurisotop; multiplicities are abbreviated as singlet (s), doublet (d), doublet of doublets (dd), and triplet (t); coupling constants are reported in Hz; IR spectra were acquired in attenuated total reflectance (ATR) mode using a FT-IR Thermo Scientific Nicolet iS10 Smart iTR instrument equipped with a diamond optical element, over a range 4000–650 cm⁻¹ (at 4 cm⁻¹ resolution). Intensities are denoted as: br = broadened signal, sh = shoulder, vs = very strong, s = strong, m = medium, w = weak and vw = very weak.