Highly Soluble Cyclic Organoalanes Based on Anionic Dicarbenes

Abstract

Cyclic organoalane compounds [(ADCAr)AlH2]2 (ADCAr = ArC{(DippN)C}2; Dipp = 2,6‐iPr2C6H3; Ar = Ph or 4‐PhC6H4 (Bp)) based on anionic dicarbene (ADC) frameworks have been reported as crystalline solids. Treatments of Li(ADCAr) with LiAlH4 at room temperature afford [(ADCAr)AlH2]2 with the concomitant release of LiH. Compounds [(ADCAr)AlH2]2 are stable crystalline solids and are freely soluble in common organic solvents. They are annulated tricyclic compounds with an almost planar central C4Al2‐core embedded between two peripheral 1,3‐imidazole (C3N2) rings. At room temperature, [(ADCPh)AlH2]2 readily reacts with CO2 to form two‐ and four‐fold hydroalumination products [(ADCPh)AlH(OCHO)]2 and [(ADCPh)Al(OCHO)2]2, respectively. Further hydroalumination reactivity of [(ADCPh)AlH2]2 has been shown with isocyanate (RNCO) and isothiocyanate (RNCS) species (R=alkyl or aryl group). All compounds have been characterized by NMR spectroscopy, mass spectrometry, and single‐crystal X‐ray diffraction.

Mixed Lithium–Aluminum Hydrides Bearing Ar-Bian Ligands: Reactivity Toward Heteroallenes

“…Thus, the former can be assigned to the single C–O bonds, while the latter to the double C=N bonds. The observed values fall within the range of respective distances in the related aluminum compounds. , …”

Ring‐Opening of 1,3‐Imidazole Based Mesoionic Carbenes (iMICs) and Ring‐Closing Clicks: Facile Access to iMIC‐Compounds

“…The C2−B1 bond length of 10 (1.614(2) Å) and 12 (1.643(3) Å) matches with that of (IPr)BH 3 (1.585(4) Å) [32] . The C2−Al1 bond length of 11 (2.050(2) Å) is similar to that of (IPr)AlH 3 (2.056(1) Å) but larger than that of a cyclic alane [( 3 ‐Ph)AlH 2 ] 2 (2.017(2) Å) [33] . The C2−Ge1 bond length of 13 (2.093(1) Å) and the C2−Sn1 bond length of 14 (2.299(2) Å) are smaller than that of NHC‐derivatives (IPr)ECl 2 (E=Ge, 2.112(2) Å; and Sn 2.341(8) Å) [30] .…”