Reactivity of Oxygen‐Bridged Geminal Al/P and Si/P Frustrated Lewis Pairs towards Heterocumulenes
Lucas Wickemeyer, Pia C. Trapp, Niklas Aders, Beate Neumann, Hans‐Georg Stammler, Norbert W. Mitzel
Abstract
Abstract The two oxygen‐bridged geminal frustrated Lewis pairs (FLP) t Bu 2 P−O−AlBis 2 (Bis=CH(SiMe 3 ) 2 ; 1 ) and t Bu 2 P−O−Si(C 2 F 5 ) 3 ( 2 ) were reacted with the heterocumulenes PhNCO, PhOCN, PhNCS, CS 2 and PhNSO as well as SO 2 . With isocyanate and cyanate, both 1 and 2 , form addition products under formation of five‐membered rings. With CS 2 , isothiocyanate and sulfinylaniline, only 1 forms stable adducts, whereas 2 shows reactivity towards sulfinylaniline, but the product decomposed after a few minutes. The reaction of 1 with SO 2 led to partial cleavage of the P−O−Al and Al−C units, as confirmed by X‐ray diffraction studies of a complex aggregate. The reaction of 2 with SO 2 affords the 1,2‐addition product. All adducts were characterized by means of multinuclear NMR spectroscopy, X‐ray crystallography and CHN analyses.