Double-Decker 3a,6a-Diaza-1,4-diphosphapentalenes in Deoxygenation Reactions: Reductive Coupling of Dimethylformamide

The reaction of double-decker ditriflates based on 2,3,5,6-tetramethyl-1 H ,4 H -3a,6a-diaza-1,4-diphosphapentalene, (MeMeDDP) 2 (OTf) 2 , and 2,5-dimethyl-3,6-diethyl-1 H ,4 H -3a,6a-diaza-1,4-diphosphapentalene, (MeEtDDP) 2 (OTf) 2 , with dimethylformamide leads to the product of the reductive coupling of the latter to 2-(dimethylimino)- N , N -dimethylethanammonium ditriflate, [(Me 2 N=CHCH 2 NHMe 2 ) 2+ (TfO − ) 2 ], and the corresponding 1,1-dioxides of 3a,6a-diaza-1,4-diphosphapentalenes, having a zwitterionic structure.