Alumination of resorcinol and hydroquinone. An easy access to bifunctional Lewis acids

Abstract The reaction of trimethylaluminum with hydrochinone and resorcinol produces [(1,4-(Me 2 AlO) 2 C 6 H 4 )—THF] 2 ( 1 ) and [(1,3-(Me 2 AlO) 2 C 6 H 4 )—THF] 2 ( 3 ) respectively. Compounds 1 and 3 are poorly soluble in common solvents but readily dissolve in pyridine to give the corresponding adducts (1,4-(Me 2 AlO) 2 C 6 H 4 )—(Py) 2 ( 2 ) and (1,3-(Me 2 AIO) 2 C 6 H 4 )—(Py) 2 ( 4 ). The reaction of 4,6-dichlorore-sorcinol with trimethylaluminum produces the soluble chlorinated analog of compound 3 [(1,3-(Me 2 AlO) 2 -4,6-Cl 2 C 6 H 2 )—THF] 2 ( 5 ). As indicated by NMR, the dimeric structure of 5 is fluxional in solution. Upon addition of chloride or t-butoxide anions to solution of 5 in THF, 27 Al NMR monitoring indicates that there is formation of anionic complexes but that the chelation of the anionic hosts by the two aluminum centers present in the [1,3-(Me 2 AlO) 2 -4,6-Cl 2 C 6 H 2 ] unit does not occur.