Reactions of β-keto sulfones with t-butyl aluminum compounds: Reinvestigation of tri-t-butyl aluminum synthesis

t-Butyl derivatives play a significant role in the organometallic chemistry of group 13 metals. It was shown on the basis of reactions of t-Bu3Al·OEt2 with [p-RC6H4S(O)2C(H)2C(Ph) = O] (where R = CH3, Cl) β-keto sulfones that the structure of the reaction products depends on the purity of the aluminum compound used. In the reactions, in addition to the expected complexes [p-RC6H4S(O2)C(H) = C (Ph)-OAl(t-Bu)2] [where R = CH3 (2); R = Cl (4)] possessing β-keto sulfone ligands, complexes with β-hydroxy sulfone ligands [p-RC6H4S(O2)C(H)2-C (Ph)-OAl(t-Bu)2] [where R = CH3 (1); R = Cl (3)] were formed. Compounds 1 and 3 were the result of the hydroalumination reaction of the β-keto sulfone ligands with t-Bu2AlH, which is an impurity of t-Bu3Al. These compounds are obtained, for the first time, as intermediate products in the hydrogenation reaction of β-keto sulfones. In this work, during t-Bu3Al·OEt2 production t-Bu2AlH·OEt2 formed as a by-product. Re-examination of reaction conditions of AlCl3 with t-BuMgCl resulted in a control of the t-Bu2AlH·OEt2 by-product content in t-Bu3Al·OEt2.