Synthesis and Biological Activity of Arylspiroborate Salts Derived from Caffeic Acid Phenethyl Ester

Figure 1

Structures of 2-aminoethoxydiphenyl borate (a), Velcade (b), AN2690 (c), and arylspiroborate salts (d).

(a)

(b)

(c)

(d)