74242-52-7Relevant academic research and scientific papers
Organometallic Compounds in Organic Synthesis. Part 10. Preparations and Some Reactions of Tricarbonyl-1,3- and -1,4-dimethoxycyclohexa-1,3-dieneiron and Related Compounds: the Preparation of the Tricarbonyl-3-methoxycyclohexadienyliumiron Cation
Birch, Arthur J.,Kelly, Lawrence F.,Thompson, David J.
, p. 1006 - 1012 (1981)
Tricarbonylcyclohexadienyliumiron cations can be regarded as synthetic equivalents, depending on the reaction sequence, either of specific aryl cations or, in the case of methoxy-derivatives, of cations derived from cyclohex-2-enones.An important series can be entered through the symmetrical 3-methoxy cation (32, R1 = R2 = H, R3 = OMe) made efficiently for the first time from tricarbonyl-1,3-dimethoxycyclohexa-1,3-dieneiron (18).It is synthetically equivalent to a meta-methoxy-benzene cation or to a 5-cation of cyclohex-2-enone.Another series of aromatic equivalents can be defined based on nucleophilic reactions at the 1-position of derivatives of tricarbonylcyclohexa-2,4-dienoneiron (33), and efficient syntheses of (33) and its 3-methoxy (35) and 4-methoxy (37) derivatives are described.The precursors for these reactions require the efficient complexation of the 1,3- or 1,4-dimethoxycyclohexadienes, which can be carried out using the conjugated, but not the unconjugated, 1,4-dienes where loss of OMe occurs.Related processes are described in preparations and uses of complexes of some 1-morpholinocyclohexa-1,3-dienes.Some mechanisms are discussed.
