4 bromoacetophenone

Acetone (≥99.9%), (3-aminopropyl)triethoxysilane (APTES; ≥ 98%), 4′-bromoacetophenone (BAP; ≥ 98%), n-dodecane (≥90%), hydrochloric acid (37% wt, aqueous solution), pyridoxal 5′-phosphate hydrate (PLP; ≥ 98%), sodium cyanoborohydride solution (5.0 M in 1 M NaOH; NaBH₃CN), sodium hydroxide aqueous solution (50%), sodium pyruvate (≥99%), tetraethyl orthosilicate (TEOS; ≥ 98%), toluene (≥99.8%, anhydrous), trimethyltetradecylammonium bromide (TTAB; ≥ 99%) were purchased from Sigma-Aldrich. 4-Bromo-α-methylbenzylamine (BMBA; ≥ 99%; racemate), dibasic potassium phosphate (≥99%), dimethylsulfoxide (DMSO; ≥ 99.8%) and monobasic potassium phosphate (≥99%) were purchased from Acros Organics. d-Alanine (≥99%) was purchased from CarlRoth. Tetrahydrofuran (THF; ≥ 99.6%) was purchased from VWR Chemicals. Heat-shrinkable polytetrafluoroethylene (PTFE) tube was purchased from RS Components. Codexis generously supplied ATA-117 transaminase. Distilled water was applied for all synthesis and treatment processes.

All reagents and solvents were used without additional purification unless specified otherwise. Poly(ethylene glycol) with molecular mass 5000 Da (PEG5k, M_w/M_n = 1.02) and 11,000 Da (PEG11k, M_w/M_n = 1.04) were purchased from Polysciences, Inc. (Warrington, PA, USA). 2,2-Bis(hydroxymethyl)propionic acid, bis-MPA, (99+%) sodium azide, and NaN₃ (98%, powder) were acquired from Acros. Sodium hydride, NaH, (95%, dry powder), 4-di(methylamino)pyridine, DMAP, (≥99%), copper(I) bromide, CuBr, (98%), propargyl bromide (80 wt.% in toluene), N,N′-dicyclohexylcarbodiimide, DCC, (99%), methyl 3,5-dihydroxybenzoate, 3,5-MDHB, (97%), 3,5-dihydroxybenzyl alcohol, 3,5-DHBA (98%), benzyl bromide (98%), sodium ascorbate, Na-Asc (≥99%), potassium carbonate, K₂CO₃ (≥98%, powder), 18-crown-6 (99%), 2,5-dihydroxybenzoic acid, 2,5-DHBA, (98%), phenylboronic acid, PBA, (95%), 4′-bromoacetophenone, 4′-BAcP, (99%), triethylamine, TEA (99.5%), and tetrahydrofuran, THF (HPLC grade) were all purchased from Sigma-Aldrich (Miwaukee, WI, USA). Dichloro-bis(benzonitrile) palladium, Pd(PhCN)₂Cl₂, (99%) was obtained from Strem Chemicals (Newburyport, MA, USA); diethyl ether, ethyl acetate, EtOAc, hexanes, and methanol (all reagent grade) were received from Pharmco, Inc. (Brookfield, CT, USA), and dichloromethane, DCM, (spectrophotometric grade) was purchased from Spectrum/Gleason Chemicals (Syracuse, NY, USA).