51508-59-9Relevant academic research and scientific papers
Transition-metal Mediated Asymmetric Synthesis. Part 5. Alternative Methods for the Formation of Tricarbonyl(η5-cyclohexadienyl)iron(1+) Salts
Alexander, Rikki P.,Stephenson, G. Richard
, p. 885 - 888 (1987)
The influence of substituents on the preparation of tricarbonyl(η5-cyclohexadienyl)iron(1+) salts by oxidation using thallium(III) tris(trifluoroacetate) and by hydride abstraction using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone-tetrafluoroboric acid has been examined.Hydride abstraction by thallium oxidation is superior to conventional methods and offers complementary regiocontrol in some cases.An example of hydride abstraction from a blocked tricarbonyl(η4-cyclohexadiene)iron complex is described.
Construction of bridged and fused bicyclic skeletons via intramolecular addition of nucleophiles to (η4-diene)Fe(CO)3 complexes bearing functionalized side chains
Yeh, Ming-Chang P.,Sheu,Fu,Tau,Chuang
, p. 5941 - 5952 (2007/10/02)
Reaction of lithium diisopropylamide (LDA) with (η4-1,3-cyclohexadiene)Fe(CO)3 complexes bearing functionalized side chains at C-5, under an atmosphere of carbon monoxide, gives bridged bicyclo[3.2.1]octene and bicyclo[3.3.1]nonene systems after electrophilic quenching, whereas larger rings cannot be obtained in this series. Under the same reaction conditions, intramolecular cyclization of acyclic (η4-1,3-butadiene)Fe(CO)3 complexes with functionalized side chains at the terminal position of the diene ligands furnishes fused bicyclo[3.3.0]octanone and bicyclo [4,3.0] nonanone derivatives after acid quenching. The iron-mediated intramolecular nucleophilic addition allows for the direct stereocontrol of four stereogenic centers of these fused bicyclic skeletons.
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 (2007/10/02)
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.
