Reaction of Dialumane Incorporating Bulky Eind Groups with Pyridines

Abstract

The reaction of the bulky Eind-based dialumane, (Eind)HAl(µ-H) 2 AlH(Eind) (1) (Eind = 1,1,3,3,5,5,7,7-octaethyl-s-hydrindacen-4-yl), with pyridines is described. When 1 was treated with pyridine (Py) in toluene, the Py adduct of aryldihydroalumane, Py→AlH 2 (Eind) (2), was initially formed. Then, the hydroalumination of Py took place to yield the Py-bound aryl(1,4-dihydropyrid-1-yl)hydroalumane, Py→AlH(1,4-dihydropyrid-1-yl)(Eind) (3). A similar reaction with a stronger Lewis base, 4-pyrrolidinopyridine (PPy), produced the stable PPy adduct, PPy→AlH 2 (Eind) (4). The resulting organoaluminum compounds have been fully characterized by NMR spectroscopy as well as X-ray crystallography. The reaction mechanism from 1 to 3 via 2 has been examined by deuterium labeling experiments using (Eind)DAl(µ-D) 2 AlD(Eind) (1-d 4 ).

Molecular Main Group Metal Hydrides

“…Since 2001, various new alkyl- and aryl-substituted alanes (R n AlH 3– n ) and aluminates [R n AlH 4– n ] − have been prepared according to previously established synthetic protocols. − From a reactivity standpoint, these organoaluminum hydrides are known to effect the hydroalumination of unsaturated substrates (e.g., alkenes, alkynes, phosphalkenes), which is a long-established reaction type , that has been used to prepare new Al–H bond-containing molecules. − A new reactivity pathway that has emerged involving carbon-supported aluminum hydrides is centered around the use of aluminum-based Lewis acids in Frustrated Lewis Pair (FLP) chemistry. , …”

A 2‐Anilidomethylpyridine Ligand Framework Showcasing Hydride Storage and Transfer Abilities in Its Aluminum Chemistry

“…Pyridine reduction by Al‐hydrides can be reversible as evident from H/D exchange studies [7e,28b] . The HOMO of 1 (Figure 3) suggests a hydridic nature of the dearomatized pyridyl backbone.…”

Nanoarchitectonics for Coordination Asymmetry and Related Chemistry

“…127 Matsuo and coworkers investigated reaction of bulky Eind-based dialumane with pyridine and 4-pyrrolidinopyridine where Eind represents 1,1,3,3,5,5,7,7-octaethyl-s-hydrindacen-4-yl. 128 Enantioselective synthesis of poly cyclic γ-lactam was reported by Tohnai, Ogoshi, and co-workers. 129 Within the oxidative cyclization on Ni(0), enantioselectivity for carbon atoms of the γ-lactams was regulated.…”