synthesize symmetrical and asymmetrical E-polymethoxystilbenes.
Experimental
Benzal bromides were prepared by bromination of substituted toluene with NBS or
bromination of benzaldehyde with boron tribromide. All compounds were characterized by
NMR, EA and MS.
In a typical coupling reaction, for example, 30.6 mg of 1a (0.10 mmol), 29.0 mg of TPMA (0.10
mmol) and 7.1 mg of copper powder (0.11 mmol) were added to an ampule equipped with a
stir bar. The ampule was degassed, backfilled four times with N2, and then left under N2.
Deoxygenated 2 mL of THF was then added. The ampule was heated at 40 °C for 1 hours. The
ampule was immersed in liquid nitrogen and the mixture was diluted with CH2Cl2 and purified
by passing through a neutral alumina column. The crude product was obtained after removal of
1
solvent under vacuum, which was measured by H-NMR using DMSO as internal standard,
giving the yield of the corresponding compounds.
Supplementary Material
Details of experimenntal and data for characterization of related compounds.
References and Notes
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