Organometallics in organic synthesis:tricarbonyl-(3-methoxycyclohexa-2,4-dien-1-yl)-iron(1+). A synthetic equivalent of the C-5 cation of cyclohexenone.

Kelly, Lawrence F.; Dahler, Peter; Narula, Acharan S.; Birch, Arthur J.

doi:10.1016/s0040-4039(01)90342-9

Cited by 16 publications

(3 citation statements)

References 27 publications

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“…41% overall yield from complex (3), which is itself prepared from 1,3-dimethoxybenzene by a four-step sequence. This approach is potentially useful for constructing cyclohexane derivatives of general structure (11) in optically active form, since we have found' that reaction of (3) with enolate nucleophiles bearing chiral auxiliaries, such as those derived from optically pure sulphoximinyl esters ti or the Evans N-acyloxazolidinone system^,^ occurs with asymmetric induction. While the enantiomeric excesses (3&70% e.e.)…”

Section: H W W )mentioning

confidence: 99%

“…We report a highly stereoselective synthesis of (2) in racemic form, which we anticipate can ultimately be modified to give optically pure material. The cyclohexadienyl-Fe(C0)3 complex ( 3) is readily prepared in multigram quantities from 1,3-dimethoxybenzene, using the method of Kelly et aL3 Treatment of (3) with NaCH(S0,Ph) C02Me gave (4) in excellent yield, which was decarboxylated without diene rearrangement or decomposition to afford (3 in 87% overall yield from (3). Treatment of (5) with pyridinium chlorochromate (PCC) gave the cyclohexenone (6) in 88% yield after purification by flash chromatography.…”

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An approach to the cyclohexyl moiety of the immunosuppressive agent FK-506

Pearson¹

1990

J. Chem. Soc., Perkin Trans. 1

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Tricarbonyl(3-met hoxycyclohexadienyl) iron hexaf luorop hosphate, which is readily prepared from 1,3-dirnethoxybenzene, was treated with the enolate of methyl phenylsulphonylacetate to give an adduct which was decarboxylated and decomplexed to give 5-phenylsulphonylmethylcyclohexenone. This compound was converted by a four-step, highly stereoselective, sequence to the trisubstituted cyclohexane (2), which represents a cyclohexyl moiety building block for FK-506.

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confidence: 99%

An approach to the cyclohexyl moiety of the immunosuppressive agent FK-506

Pearson¹

1990

J. Chem. Soc., Perkin Trans. 1

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“…Pearson described an oxidative method for the direct decomplexation of CpMo(CO) 2 (π-allyl) complexes accompanied by introduction of an OH group 13a. In a related transformation, cyclic Mo complexes bearing a methoxy group 1f,g,20 at a terminus of the π-allylic system have been oxidatively demetalated with ceric ammonium nitrate or CuCl 2 to afford the corresponding α,β-unsaturated ketones. , As a complement to the preceding demetalation procedures, we report herein a novel, efficient, and general oxidative demetalation of (η 3 -allyl)molybdenum complexes that allows the introduction of a carbonyl group at an allylic terminus of the π-system. The process takes place with high regiocontrol and leads to unsaturated ketones and lactones.…”

Section: Introductionmentioning

confidence: 99%

New Oxidative Demetalation Protocol for Molybdenum π-Complexes: Enantiocontrolled Synthesis of Unsaturated Ketones and Lactones

2002

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The Chemistry of Diene–Iron and Dienyl–Iron Complexes

Бауер

Knölker

2013

Patai's Chemistry of Functional Groups

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(η 4 ‐Diene)iron complexes and η 5 ‐dienyliumiron complex salts represent intriguing structures with planar π‐donating C 4 or C 5 ligands attached to the central iron atom. In many cases, they are rather stable compounds due to an 18‐electron count at the iron center. Tricarbonyl(η 4 ‐diene)iron complexes are formed from cyclic and acylic 1,3‐dienes and a tricarbonyliron source. Under certain conditions 1,4‐dienes can be employed with concomitant rearragement of the double bonds. The tricarbonyliron source can be a binary carbonyliron complex or a tricarbonyliron transfer reagent. (η 4 ‐1‐Azabutadiene)tricarbonyliron complexes have been proven to transfer the tricarbonyliron unit efficiently to the diene system. 1‐Azabutadiene ligands can even be employed in catalytic amounts. Chiral 1‐azabutadiene ligands enable the catalytic asymmetric synthesis of planar chiral (η 4 ‐diene)iron complexes. The tricarbonyliron fragment in (η 4 ‐diene)iron complexes is shielding one side of the diene system. Thus, it can be utilized to control stereoselective reactions in its proximity. Moreover, due to their stability (η 4 ‐diene)iron complexes can be employed as protected 1,3‐dienes. η 5 ‐Dienyliumiron complexes are generated from (η 4 ‐diene)iron complexes by two principal methods. Either by hydride abstraction at the α‐position of the diene ligand using triphenylcarbenium salts or by elimination of leaving groups adjacent to the diene system. η 5 ‐Dienyliumiron complexes are versatile electrophiles which react with a large variety of nucleophiles leading to functionalized (η 4 ‐diene)iron complexes. In most cases, nucleophilic attack at the terminus of the co‐ordinated dienylium system is preferred. Especially with C‐nucleophiles, the reaction is extremely useful for the construction of natural products or advanced synthetic precursors. Employment of substituted anilines as nucleophiles has paved the way to the total synthesis of a large number of biologically active carbazole alkaloids. After exploiting the activating, protecting or stereodirecting effect of the iron complex, the organic ligand is disengaged from the metal. A variety of mild demetalation procedures has been developed for this purpose. In addition to the stoichiometric reactions, first examples of catalytic applications of (diene)iron complexes are dicussed in this chapter.

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Organometallics in organic synthesis:tricarbonyl-(3-methoxycyclohexa-2,4-dien-1-yl)-iron(1+). A synthetic equivalent of the C-5 cation of cyclohexenone.

Cited by 16 publications

References 27 publications

An approach to the cyclohexyl moiety of the immunosuppressive agent FK-506

An approach to the cyclohexyl moiety of the immunosuppressive agent FK-506

New Oxidative Demetalation Protocol for Molybdenum π-Complexes: Enantiocontrolled Synthesis of Unsaturated Ketones and Lactones

The Chemistry of Diene–Iron and Dienyl–Iron Complexes

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