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Neue Synthesen mit 1,3‐ambident‐nucleophilen Phosphor‐Yliden, VII. Heterocyclische Triphenylphosphonium‐chloride, Triphenylphosphonio‐olate, acyclische Triphenylphosphonio‐thiolate und ihre Wittig‐Derivate
Author(s) -
Capuano Lilly,
Drescher Stefan,
Huch Volker
Publication year - 1993
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.199319930123
Subject(s) - chemistry , wittig reaction , medicinal chemistry , chloride , oxalyl chloride , ylide , imine , pyridine , nucleophile , intramolecular force , organic chemistry , catalysis
Syntheses with 1,3‐Ambident‐Nucleophilic Phosphorus Ylides, VII. – Heterocyclic Triphenylphosphonium Chlorides, Triphenylphosphonio‐Olates, Acyclic Triphenylphosphonio‐Thiolates and Their Wittig Derivatives Under mild conditions, benzoylmethylenetriphenylphosphorane ( 1b ) reacts readily with oxalyl chloride to give the unstable 4‐(4,5‐dihydro‐4,5‐dioxo‐2‐phenyl‐3‐furyl)triphenylphosphonium chloride ( 3b ). This undergoes rapid hydrolysis to afford the triphenylphosphonium chloride 4 of benzoylpyruvic acid. Thermolysis of 3b or 4 results in the formation of 2‐(triphenylphosphoranyliden)indan‐1,3‐dione ( 10 ), the structure of which was established by X‐ray diffraction analysis. – With phenylmalonyl chloride, the title compounds 1a , b , d react by formation of the triphenylphosphonio‐olates 7 of pyridine‐, pyran‐ and thiopyran‐dione, respectively. – The (thioaroylmethylene)triphenylphosphoranes 1e , f react with benzonitrile imine 12 to give the red hydrazonotriphenylphosphoniothiolates 16 , the structures of which have been elucidated by an X‐ray diffraction analysis. Under rigorous conditions, compounds 16 undergo an intramolecular Wittig‐type reaction leading to pyrazoles 14 .