Cobalt Porphyrin Recrystallization and Organic Electrophiles Preparation

Cobalt(II) tetraphenylporphyrin (Co^IITPP) (TCI America, >80.0%) was recrystallized from methylene chloride (Fisher Chemical, HPLC) before use: ~1 g of as-received Co^IITPP was dissolved in ~500 ml of methylene chloride via sonication for ~2 h; the solution was filtered with 0.45 μm syringe filters (VWR), transferred in a crystallization dish (Pyrex), and evaporated under ambient atmosphere overnight; the recrystallized solid was dried at 60 °C and stored in an Argon-filled glovebox. Tetrabutylammonium hexafluorophosphate (NBu₄PF₆) (TCI America, >98.0%) was dried at 90 °C under vacuum and stored in the glovebox. Dimethylformamide (DMF) (Sigma-Aldrich, anhydrous, 99.8%) was stored in the glovebox and used as received.
A diverse scope of organic electrophiles was studied in this work. Purchased from Sigma-Aldrich were 1-bromobutane (n-BuBr) (99%), 1-iodobutane (n-BuI) (99%, stabilized with copper), 1-bromo-2-methylpropane (i-BuBr) (99%), dichloromethane (CH₂Cl₂) (anhydrous, ≥99.8%, stabilized with amylene), chloroacetonitrile (ClCH₂CN) (99%), acetonitrile (CH₃CN) (anhydrous, 99.8%), benzyl bromide-α,α-d₂ (PhCD₂Br) (98 atom% D), 4-methylbenzyl bromide (p-Me-PhCH₂Br) (97%), 4-(trifluoromethoxy)benzyl bromide (p-F₃CO-PhCH₂Br) (97%), methyl 4-(bromomethyl)benzoate (p-MeO₂C-PhCH₂Br) (98%), and 4-(bromomethyl)benzophenone (p-PhOC-PhCH₂Br) (96%). Purchased from TCI America were 1-bromohexane (n-HexBr) (>98.0%), 1-bromooctane (n-OctBr) (>98.0%), 2-bromobutane (2-BuBr) (>98.0%), 1-chlorobutane (n-BuCl) (>99.0%), 3-chloropropionitrile (Cl(CH₂)₂CN) (>98.0%), 4-chlorobutyronitrile (Cl(CH₂)₃CN) (>97.0%), 5-chlorovaleronitrile (Cl(CH₂)₄CN) (>97.0%), 4-bromobutyronitrile (Br(CH₂)₃CN) (>97.0%), and benzyl bromide (PhCH₂Br) (>98.0%, stabilized with propylene oxide). Purchased from Oakwood Chemical were neopentyl iodide (Me₃CCH₂I) (98%), 4-iodobutyronitrile (I(CH₂)₃CN) (97%), and 1-(bromomethyl)-4-methoxybenzene (p-MeO-PhCH₂Br) (stabilized with K₂CO₃). Purchased from Synquest Laboratories were 4-fluorobenzyl bromide (p-F-PhCH₂Br) (98%), 4-(trifluoromethyl)benzyl bromide (p-F₃C-PhCH₂Br) (98%), and 4-cyanobenzyl bromide (p-NC-PhCH₂Br) (98%). Purchased from Cambridge Isotope Laboratories were n-BuBr-d₉ (98%) and n-BuI-d₉ (98%, stabilized with copper). Purchased from AK Scientific was 1-(bromomethyl)-4-phenoxybenzene (p-PhO-PhCH₂Br) (95%). Purchased from Thermo Scientific Chemicals was (1-bromoethyl)benzene (PhCH(CH₃)Br) (97%). Among all the organic electrophiles mentioned above, solid chemicals were stored in the glovebox and used as received, whereas liquid chemicals were transferred in a Schlenk flask, evacuated under vacuum on a Schlenk line, brought into the glovebox, and dried over 3 Å molecular sieves (Sigma-Aldrich) before use.