STUDIES ON PHOSPHONIUM YLIDES-XIII THE REACTIVITY OF N,N′-2,5-CYCLOHEXADIENES-1,4-DIYLIDENEBIS [BENZENESULFONAMIDE] TOWARDS WITTIG REAGENTS

Abstract

Cyanomethylenetriphenylphosphorane (IIa) reacts with N,N′-2,5-cyclohexadiene-1,4-diylidenebis (benzenesulfonamide] (Ia) affording the new azacyclopropane adduct IIIa. On the other hand, methylenetriphenylphosphoranes (IIb-d) react with quinoneimine (Ia) and its 2-chloro-derivative (Ib) yielding the corresponding ylid-phosphorane adducts IIIb-g. Structural reasoning for compounds III was based on compatible analytical and spectral data (IR, ¹H, ³¹P, ¹³C, NMR and MS). A mechanism is proposed to explain the formation of compounds III.

Key Words:

• N,N′-2,5-Cyclohexadiene-1,4-diylidenebis [benzenesulfonamides] (Ia,b)
• Wittig reagents (II)
• azacyclopropane adduct (IIIa)
• alkyl-1-((benzenesulfonyl)amino]-4-2,5-cyclohexadiene-1-acetate (IIIb,c)
• N-4-(benzenesulfonyl)amino]-4-[2-oxo-2-phenyl-1-(triphenylphosphoranylidene)ethyl-2,5-cyclohexadien-1-ylidene] benzenesulfonamide (IIIb)