Facile Generation of Aluminum 1,2-Dihydropyridyl and Hydroxyl Derivatives from an Aluminum Cyclopropene Analogue

Reaction of LAl(η 2 -Me 3 SiC 2 SiMe 3 ) (1; L = HC[(CMe)-(NDipp)] 2 , Dipp = 2,6-iPr 2 C 6 H 3 ) with pyridine afforded the (1,2-dihydropyridyl)aluminum species LAl[C 2 (SiMe 3 ) 2 CHN-(C 4 H 4 )] (2), having an AlC 3 N five-membered ring, as a major product via insertion into one of the Al-C bonds, while hydrolysis of 1 at low temperature resulted in ring cleavage to yield the monomeric aluminum alkenyl hydroxide LAl(OH)-[C(SiMe 3 )CH(SiMe 3 )] (3). The molecular structures of 2 and 3 were determined by X-ray single-crystal analysis.