P toluenesulfonic acid tsoh

The solvents acetonitrile, N,N-dimethylformamide (DMF), dichloromethane, diethyl ether, and chlorobenzene were purchased from Fisher Scientific or Sigma Aldrich. Prior to use, the solvents were distilled over calcium hydride or filtered over dried alumina and stored over molecular sieves. Benzo[c]cinnoline (bncn) and p-toluenesulfonic acid (TsOH) were purchased from Sigma-Aldrich, Rh₂(OAc)₄ (OAc = acetate) and 1-benzyl-1,4-dihydronicotinamide (BNAH) were obtained from TCI. Cobaltocene was stored in a glove box preventing it from exposure to moisture and oxygen. Synthetic procedures were performed under a N₂ atmosphere and the purification processes were opened to air; the general procedure is shown in Scheme S1† and 1H NMR spectra of the starting materials and products are shown in Fig. S1–S6 (ESI†). The ligands diphenylbenzamidine (DPhB) and diphenyltriazenide (DPhTA), as well as the precursor cis-[Rh₂(DPhTA)₂(CH₃CN)₆][BF₄]₂ were synthesized according to literature procedures.^{37,38 (link)}

Thymol blue sodium salt (ACS reagent), bromophenol
blue (ACS reagent), bromocresol green (ACS reagent), methyl red (Fluka
Analytical), nitrazine yellow (indicator grade), methyltriethoxysilane
(technical grade, 90%), triethoxy(octyl)silane (≥97.5%), 2-methoxyethanol
(anhydrous 99.8%), propylene glycol methyl ether acetate (Reagent
Plus ≥99.5%), polyethylene glycol tert-octylphenyl
ether (laboratory grade), pararosaniline base, N,N-dimethyl-4,4′-azodianiline (ACROS Organics, 95%), p-toluenesulfonic acid (TsOH), and sulfuric acid (H₂SO₄) were purchased from Sigma-Aldrich (Arklow,
Co. Wicklow, Ireland). Analytical standards were also purchased from
Sigma-Aldrich, Ireland. Substrates (TLC plates, Polygram CEL 300)
were obtained from Machery-Nagel GmbH (Düren, Germany). Water
used was high-purity Milli-Q water (Millipore >18MΩcm). SPME
fibers comprising 50/30 μm divinylbenzene/carboxen/polydimethylsiloxane
(DVB/Car/PDMS) StableFlex (2 cm) assemblies were purchased from Supelco
Corp. (Bellefonte, PA, USA). Fibers were conditioned at 250 °C
for 25 min before use each day. The cooking oils (rapeseed oil, groundnut
oil, extra virgin olive oil, and sunflower oil) were purchased from
a local supermarket in Santry, Dublin 9, Ireland.