Study on the preparation method of (S)-1-(diphenylphosphate)-2-[(S)-4-isopropyloxazolin-2-yl]ferrocene_Industrial additives

Background and overview^[1]

Compared with active epoxy compounds, ferrocene is a metal-organic complex and has good stability in both acidic and alkaline environments. Since ferrocene was first discovered in 1951, researchers have synthesized a series of ferrocene derivatives containing epoxy structures such as (S)-1-(diphenylphosphate)-2-[(S)- 4-Isopropyloxazolin-2-yl]ferrocene, research in this field has attracted the attention of scholars at home and abroad.

Preparation^[1]

Oxazoline (S)-3a (0.158 g, 0.53 mmol) was added to a flame-dried Schlenk tube under an argon atmosphere and dissolved in anhydrous ether (6 mL). Tetramethylethylenediamine (0.100 ml, 0.70 mmol) was added, then the orange solution was cooled to -78 °C and stirred for 5 min, then sec-butyllithium (1.4 M) (0.500 ml, 0.70 mmol) was added slowly. After stirring for 2 h, the mixture was heated to 0 °C and freshly distilled chlorodiphenylphosphine (0.120 ml, 0.70 mmol) was added via syringe. The reaction was allowed to warm to room temperature and then diluted with diethyl ether for an additional 10 minutes and then quenched with saturated aqueous sodium bicarbonate solution. The organic matter was separated with water, dried over magnesium sulfate, and the solvent was removed in vacuo to obtain the crude product. Column chromatography (SiO₂, 10% EtOAc in hexane) eluting as orange solid diastereomers (0.11 g, 43%):

R_f0.23 (10 % EtOAc in hexane); νmax (film)/cm^-1 3072, 3048,2955, 2934, 1658 (C=N) ; [α]D22.6°C = +92 (c = 0.1, EtOH);¹H NMR (500 MHz, CDCl₃) δ 7.51 –

7.46 (2H, m, o-Ph-H), 7.38-7.34 (3H, m, m+p-Ph-H), 7.25-7.17 (5H, m, o,m+p-Ph-H ), 4.99(1H, brs, Cp-H), 4.37 (1H, t, J = 2.4 Hz, Cp-H), 4.26 (1H, dd, J = 9.4, 8.4 Hz, CHH), 4.22 (5H, s ,CpH), 3.86 (1H, ddd, J = 9.5, 8.0, 5.7 Hz, CH), 3.68 (1H, t, J = 8.2 Hz, CHH), 3.63 – 3.59 (1H, m,Cp-H), 1.71 – 1.63 (1H, m, iPr(H)), 0.82 (3H, d, J = 6.8 Hz, iPr(Me)), 0.69 (3H, d, J = 6.8 Hz,iPr(Me)); ¹³C NMR (125 MHz, CDCl₃) δ 165.4 (C7), 139.7 (d, J = 12.8 Hz, C12), 138.3 (d, J = 13.4Hz, C12′ ), 135.0 (d, J = 21.4 Hz, C13′), 132.6 (d, J = 19.4 Hz, C13), 129.1 (C15′), 128.3 (d, J = 7.2Hz, C14′), 128.2 (d, J = 6 antistatic agent Irgastat P18.8 Hz, C14), 128.0 (C15), 78.72 (dbyk adhesion promoter, J = 15.2 Hz, C2), 75.5 (d, J = 18.4 Hz, C6), 74.0 ( d, J = 4.1 Hz, C3), 72.3 (C5), 72.2 (C9), 70.9 (C1+4), 69.8 (C8

), 29.9 (C10), 18.8 (C11′),17.7 (C11); ³¹P NMR (202 MHz, CDCl₃) δ -16.87 (PPh2 ).