Reaction Steps
The general procedure described by Gao et al., (2004) Org. Lett., 6:1837, was used to couple 5,15-dibromo-10,20-diphenylporphyrin (31.0 mg, 0.05 mmol) with (R)-(+)-4-benzyl-2-oxazolidinone (70.8 mg, 0.4 mmol), using Pd2(dba)3 (2.3 mg, 0.0025 mmol) and Xantphos (5.78 mg, 0.01 mmol) in the presence of Cs2CO3 (65.2 mg, 0.2 mmol). The reaction was conducted in THF at 68° C. for 22 h., The title compound was isolated by flash chromatography (silica gel, methylene chloride:ethyl acetate (v/v)=9:1) as a purple mixture of two atropic isomers (25 mg, 62%, α,α/α,β=50%/50%). 1H NMR (300 MHz, CDCl3): δ 9.46 (d, J=5.1 Hz, 4H), 9.42 (d, J=4.8 Hz, 4H), 9.24 (t, J=4.2 Hz, 4H), 9.00 (d, J=4.8 Hz, 2H), 8.96 (d, J=4.2 Hz, 4H), 8.93 (d, J=4.8 Hz, 2H), 8.32 (d, J=4.8 Hz, 2H), 8.20 (t, J=7.2 Hz, 4H), 8.06 (d, J=4.8 Hz, 2H), 7.79 (m, 12H), 7.07 (m, 6H), 7.02 (m, 6H), 6.83 (m, 8H), 5.35 (m, 2H), 5.23 (m, 2H), 5.00 (dd, J=9.0 Hz, 4H), 4.82 (dd, J=9.0 Hz, 4H), 3.13-3.30 (m, 4H), 2.94 (dd, J=13.2, 3.3 Hz, 2H), 2.70 (dd, J=13.2, 3.3 Hz, 2H), −2.84 (s, 2H), −2.89 (s, 2H); 13C NMR (75 MHz, CDCl3): δ 147.1, 140.1, 140.9, 135.0, 134.6, 128.8, 128.7, 128.2, 127.1, 126.9, 126.8, 121.4, 111.5, 68.3, 66.4, 40.4, 40.3. UV-vis (CH2Cl2, λmax, nm): 412, 526, 558. HRMS-MALDI ([M+H]+): calcd for C52H41N6O4, 813.3184, found 813.3194 with an isotope distribution pattern that is the same as calculated one.
