合成路线1

A new enantioselective synthesis of R-(-)-denopamine has been published: The silylation of 4-hydroxyphenacyl chloride (I) with tert-butyldimethylchlorosilane (II) and imidazole in THF gives the silylated compound (III), which is enantioselectively reduced with borane, using the (R)-oxaazaborilidine (IV) as optically active catalyst in THF, yielding (R)-2-chloro-1-[4-(tert-butyldimethylsilyloxy)phenyl]ethanol (V). The reaction of (V) with NaI in refluxing acetone affords the corresponding iodo-alcohol (VI), which is protected with triethylchlorosilane and imidazole in DMF to give the fully silylated compound (VIII). The condensation of (VIII) with 2-(3,4-dimethoxyphenyl)ethylamine (IX) by means of triethylamine in THF at 100 C in a sealed tube yields the fully silylated denopamine (X), which is finally deprotected by a treatment with KF and HCl in methanol.