Regiospecific conversion of oxiranes, oxetanes, and lactones into difunctional nitrogen compounds via aminosilanes and aminostannanes

Abstract

The insertion reactions of diethylaminotrimethylsilane (TMSDEA) and diethylaminotrimethylstannane (TMSnDEA) into oxirane, oxetane, and lactone rings are reported. Regioisomerically pure β- and γ-amino alcohols were obtained, with AlCl₃ or Et₂AlCl catalysis, from monoalkyloxiranes and monoalkyl-and aryl-oxetanes respectively, whereas, in the majority of cases, reactions involving polysubstituted oxiranes resulted in a loss of regioselectivity. Ring-opening reactions of the lactone rings with TMSDEA led, on the other hand, to β-amino acids or to ω-hydroxyamides depending upon the ring size.

With TMSnDEA, spontaneous ring cleavage of the alkyloxiranes and of β-propiolactone occurred with reversed regioselectivity, while the oxetanes and γ- and δ-lactones were opened with the same regiochemistry as that found with TMSDEA for the same ring systems.