Abstract:Hydroalumination of H 10 C 5 N-N=C(Ad) with HAliBu 2 yielded the hydrazide H 10 C 5 N-N(AliBu 2 )Ad (4; Ad = adamantyl, NC 5 H 10 = piperidinyl). Compound 4 is monomeric and contains a highly strained AlN 2 heterocycle formed by a donor-acceptor interaction between the Al atom and the -N atom of the hydrazine. Two equivalents of the hydride afforded an adduct with an HAliBu 2 molecule coordinated to 4 by an Al-N and a 3c-2e Al-H-Al bond (5). tBuN=C=O did not insert into the relatively weak Al←N donor-acceptor bond of 4; instead, insertion

The active Lewis pairs (ALPs) 2,6-Me2H8C5N–C(H) = C(SiMe3)–AlR2 (1a: R = tBu, 1b, R = iBu) have strained AlC2N heterocycles and relatively weak Al–N bonds. They react readily with a series of organic azides R′N3 [R′ = Ph, CH2C6H4(4-tBu), tBu, SiMe3, CH2Ph] by cleavage of the heterocycles and addition of the azides with their α-N atoms to the Al atom. The Al–N interactions result in an activation of the azide groups which insert into the C–Si bonds of the vinyl groups with their terminal γ-N atoms. Compounds with approximately planar five-membered AlCN3 heterocycles and intact N3 groups are formed in highly selective reactions.