915980-24-4Relevant academic research and scientific papers
Facile synthesis of monomeric alumatranes
Su, Weiping,Kim, Youngjo,Ellern, Arkady,Guzei, Ilia A.,Verkade, John G.
, p. 13727 - 13735 (2007/10/03)
Alumatranes, tricyclic neutral molecules featuring a transannular N → Al bond, can act as Lewis acids that activate substrates in the axial coordination site. Treatment of tris(2-hydroxy-3,5-dimethylbenzyl)-amine with AlMe3 afforded dimeric (AIL)2 1 [wherein L = tris(2-oxy-3,5-dimethylbenzyl)amine]. X-ray diffraction analysis revealed bridging between AIL monomers by two Al-O bonds. Reactions of 1 with substrates containing O or N donors generated the alumatranes THF-AIL 2, PhCHO-AIL 3, H2NCH2CH2-NH2-AIL 4, and [PhO-AIL]- 5, in which the apical added ligand on the five-coordinate aluminum center causes variation in the transannular bond distance. Water coordinates with 1 a -20 0C to form the alumatrane H2O-AIL 6 that undergoes partial hydrolysis at room temperature to produce 7, which X-ray crystallography showed to be composed of four AIL fragments linked by an (H 2O)2(HO)2Al(OH)2Al(OH) 2-(H2O)2 framework in which the O 4AlO2AlO4 moiety is of local D2h symmetry. According to X-ray analysis, 7 can crystallize in at least two polymorphic modifications: triclinic 7a and monoclinic 7b. The reaction of 3 with water also generated 6 and 7, depending on the reaction temperature. Dimeric 1 was found to promote the reaction of benzaldehyde with trimethylsilyl cyanide at room temperature to provide 2-trimethylsilyoxyphenylacetonitrile in 95% yield.
