Facile Synthesis of Cyclopropene Analogues of Aluminum and an Aluminum Pinacolate, and the Reactivity of LAl[η²-C₂(SiMe₃)₂] toward Unsaturated Molecules (L = HC[(CMe)(NAr)]₂, Ar = 2,6-i-Pr₂C₆H₃)

Abstract

Reduction of LAlI(2) (1) (L = HC[(CMe)(NAr)](2), Ar = 2,6-i-Pr(2)C(6)H(3)) with potassium in the presence of alkynes C(2)(SiMe(3))(2), C(2)Ph(2), and C(2)Ph(SiMe(3)) yielded the first neutral cyclopropene analogues of aluminum LAl[eta(2)-C(2)(SiMe(3))(2)] (3), LAl(eta(2)-C(2)Ph(2)) (4), and LAl[eta(2)-C(2)Ph(SiMe(3))] (5), respectively, whereas reduction of 1 in the presence of Ph(2)CO gave an aluminum pinacolate LAl[O(2)(CPh(2))(2)] (6), irrespective of the amount of Ph(2)CO employed. The unsaturated molecules CO(2), Ph(2)CO, and PhCN inserted into one of the Al-C bonds of 3 leading to ring enlargement to give novel aluminum five-membered heterocyclic systems LAl[OC(O)C(2)(SiMe(3))(2)] (7), LAl[OC(Ph)(2)C(2)(SiMe(3))(2)] (8), and LAl[NC(Ph)C(2)(SiMe(3))(2)] (9) in high yields. In contrast, 3 reacted with t-BuCN, 2,6-Trip(2)C(6)H(3)N(3) (Trip = 2,4,6-i-Pr(3)C(6)H(2)), and Ph(3)SiN(3) resulting in the displacement of the alkyne moiety to afford LAl[N(2)(Ct-Bu)(2)] (10) with an unprecedented aluminum-containing imidazole ring, and the first monomeric aluminum imides LAlNC(6)H(3)-2,6-Trip(2) (11) and LAlNSiPh(3) (12). All compounds have been characterized spectroscopically. The variable-temperature (1)H NMR studies of 3 and ESR measurements of 3 and 4 suggest that the Al-C-C three-membered-ring systems can be best described as metallacyclopropenes. The (27)Al NMR resonances of 2 and 3 are reported and compared. Molecular structures of compounds 3, 4, 6.OEt(2), 8.OEt(2), and 9 were determined by single-crystal X-ray structural analysis.

Nitril‐Nitril‐C‐C‐Kupplungen an Gruppe‐4‐Metallocenen zu 1‐Metalla‐2,5‐diazacyclopenta‐2,4‐dienen und deren Reaktionen

“…Allerdings sind stabile 1-Metalla-2,5-diazacyclopenta-2,4-diene (H) als Produkte von Nitril-Nitril-Kupplungen äußerst selten, und es gibt nach unserer Kenntnis bisher nur zwei Hinweise für eine derartige Reaktion. Für Aluminium [24] und Zirconium [25] Die Tatsache, dass es nur wenige Informationen zur Bildung von 1-Metalla-2,5-diazacyclopenta-2,4-dienen über eine Nitril-Nitril-Kupplung gibt, motivierte uns, die Reaktionen von Metallocen-Komplexen der Gruppe 4 mit Nitrilen im Detail zu untersuchen. Erst kürzlich haben wir diesbezüglich erste Ergebnisse über die Reaktionen mit den mono-und diphenylierten Acetonitrilen PhCH 2 CN und Ph 2 CHCN verçffentlicht, die, in Abhängigkeit vom Metall und den Cp-Liganden, zu verschiedensten Produkten führten.…”

[{HC(CMeNAr)2}2Al2P4] (Ar=2,6‐iPr2C6H3): A Reduction to a Formal {P4}4−Charged Species

“…To our knowledge, the study of the chemical behavior of 1 is limited so far to coupling reactions. [7,8] Compounds containing the heavy elements of Group 13 and 15 are used as models in bonding theory [9] and as precursors for semiconducting materials.[10] Herein we report the reaction of 1 with white phosphorus to yield the first main-group complex of composition [(LAl) 2 P 4 ] (2) containing the {P 4 } 4À species. Treatment of two equivalents of 1 with white phosphorus at room temperature leads to 2 in good yield (Scheme 1).…”

Synthesis and Characterization of [Ar′GaC(Ph)CH]2 and K2[Ar′GaC(Ph)CH]2⋅OEt2: From Digallene to Digallacyclohexadiene to Digallatabenzene

“…Compound 3 and 4 were characterized spectroscopically and by X-ray crystallography. [12] The reaction of Ar'GaGaAr' with HC CPh occurs readily to give the new six-membered-ring product 3. The structure of 3 ( Figure 1) shows that the {C 4 Ga 2 } ring has a distorted, flattened-chair conformation.…”

“…[11,13] With acetylene, the Al I species :AlL (L = [(2,6-iPr 2 C 6 H 3 )N = CMe] 2 CH) forms LAl(h 2 -C 2 H 2 ) at low temperature.…”

“…[17] Experimental Section All manipulations were carried out under anaerobic and anhydrous conditions. 1 H and 13 C NMR spectra were recorded on a Varian 600 spectrometer and referenced to known standards.…”