Isobutanol

Aluminium chloride (99%), ammonium bicarbonate (≥99.5%), L-aspartic acid disodium salt (≥98%), L-alanine (≥99.5), β-alanine (≥99%), calcium chloride dihydrate (≥99%), chloroform (100–200 ppm amylene stabiliser, ≥99.5), cobalt chloride hexahydrate (cell culture grade), glycine (≥99%), glutamate (≥99%), guanidine chloride solution (8 M), hydrochloric acid (≥37%), isobutyl chloroformate (98%), manganese sulfate (cell culture grade), oxaloacetic acid (≥97%), potassium chloride (99%), potassium phosphate monobasic (99.5–101.0%), pyridine (98%), pyridoxamine dihydrochloride (cell culture grade), pyridoxal hydrochloride (≥99%), L-serine (≥99%), sodium acetate (99–101%), sodium orthovanadate (99.98%), and zinc chloride x (≥98%) were purchased from Sigma. Boric acid (analytical grade), water (HPLC grade) and acetonitrile (HPLC grade) were purchased from Fischer. Copper sulfate hexahydrate (98.0–102.0%), isobutanol (99%), magnesium chloride hexahydrate (≥98%), and nickel chloride hexahydrate (98%) were from Alfa Aesar. Sodium hydroxide was purchased from VWR, and sodium chloride (research-grade) was purchased from Millipore. Ammonium chloride (analysis-grade) was from Acros and 9-fluroenylmethoxycarbonyl chloride (97%) was from Novabiochem. Helium (99.995%) and Nitrogen (99.998%) were purchased from BOC.

All chemicals and reagents were used without further purification, with the exception of tetrabutylammonium hexafluorophosphate which was recrystallised from hot ethanol. Chloroacetonitrile (98 %), sodium hydroxide (pellets, 98 %), N,N‐dimethylformamide (anhydrous, amine‐free, 99.9 %), isobutanol (99 %) and 2,2,2‐tiflouroethanol (99+%) were purchased from Alfa Aesar. Sulfur (refined, 99.5 %), acetonitrile (anhydrous, extra dry, Acroseal®, 99.9+%) and tetraethylammonium chloride hydrate (99 %) were purchased from Acros Organics. Isopropanol (reagent grade, 99.5 %), ethanol (HPLC grade, 99.8 %) and iron(III) chloride (anhydrous, 99 %) were purchased from Fisher Scientific. Tetrabutylammonium hexafluorophosphate (>98 %) was purchased from Tokyo Chemical Industry UK Ltd. Ferrocene (98 %) was purchased from Sigma Aldrich.