Nucleophilic and organometallic displacement reactions of allylic compounds: stereo-and regiochemistry

Magid, Ronald M.

doi:10.1016/0040-4020(80)80203-1

Cited by 380 publications

(115 citation statements)

References 223 publications

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“…To avoid further confusion in nomenclature, the name salutaridinol without a Roman numeral is now used for the biologically active compound and 7-epi-salutaridinol (7R) for the biologically inactive compound. The biologically active salutaridinol (7S) possesses the correct stereochemical configuration for an allylic syn-displacement of the activated hydroxyl group by the phenolic hydroxyl group that follows the precedented stereocontrol for S N 2Ј substitution at cyclohexene rings (12,13).…”

Section: Discussionmentioning

confidence: 99%

Acetyl Coenzyme A:Salutaridinol-7-O-Acetyltransferase from Papaver somniferum Plant Cell Cultures:

Lenz

Zenk

1995

Journal of Biological Chemistry

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Acetyl coenzyme A:salutaridinol-7-O-acetyltransferase, a highly substrate-specific enzyme, has been purified nearly 3,000-fold to homogeneity from Papaver somniferum plant cell suspension cultures. Purification was achieved by fractionated ammonium sulfate precipitation, dye-ligand affinity chromatography on matrex red A, gel filtration, ion exchange chromatography on Mono Q and a second dye-ligand affinity chromatography on fractogel TSK AF Blue. The purified enzyme was a single polypeptide with an M r ‫؍‬ 50,000 displaying an isoelectric point of 4.8, a pH optimum between pH 6 and 9 and a temperature optimum at 47°C. The K m values for the substrate salutaridinol and the co-substrate acetyl coenzyme A were 7 and 46 M, respectively. Salutaridinol-7-O-acetyltransferase catalyzes the stoichiometric transfer of the acetyl group from acetyl coenzyme A to the 7-OH group of salutaridinol yielding salutaridinol-7-O-acetate, which is a new intermediate in morphine biosynthesis. Salutaridinol-7-O-acetate undergoes a subsequent spontaneous allylic elimination at pH 8 -9, leading to the formation of thebaine (1), the first morphinan alkaloid with the complete pentacyclic ring system, or at pH 7 leading to dibenz[d,f]azonine alkaloids that contain a nine-membered ring. Acetylation and subsequent allylic elimination is a new enzymic mechanism in alkaloid biosynthesis, which in the poppy plant can transform one precursor into alkaloids possessing markedly different ring systems, depending on the reaction pH.

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Section: Discussionmentioning

confidence: 99%

Acetyl Coenzyme A:Salutaridinol-7-O-Acetyltransferase from Papaver somniferum Plant Cell Cultures:

Lenz

Zenk

1995

Journal of Biological Chemistry

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“…This mechanism is called second-order allylic C2ϪC2Ј [a] 1.4765 (7) rearrangement (S N 2Ј). [14] It is sometimes encountered when there is a sterically hindered α substituent present, when a large nucleophile is used, or when certain leaving groups angle are attached at the allylic carbon atom. [13] In the present case, the second situation appears to be operative; the bulky C6ϪN1ϪC2 117.14(3) N1ϪC2ϪC3 121.…”

Section: N1ϫc2mentioning

confidence: 99%

Synthesis and Experimental Electron Density of Bis(heterocyclic) Azines: The Case of 6,6′-Bis(chloromethyl)-2,2′-bipyrazine

Bodar-Houillon

Elissami

Marsura³

et al. 1999

Eur. J. Org. Chem.

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The synthesis and reactivity of mono‐ and bis(chloromethyl)‐2,2′‐bipyrazines toward nucleophiles are reported. The reactivity of the bipyrazine ring is explained in terms of allylic substitution and rearrangement mechanisms. A new family of monofunctionalized bipyrazine derivatives as molecular building blocks for supermolecules has been obtained, opening access to unsymmetrical ligands. The low‐temperature crystallographic structure and the experimental electron density distribution of 6,6′‐bis(chloromethyl)‐2,2′‐bipyrazine have been determined on the basis of high‐resolution X‐ray diffraction data. The electron density of the molecule has been accurately analyzed using the topological properties of its gradient and Laplacian features. The reactivity of these bidentate molecules in metal complexation is related to the shape of the atomic basins and may be explained in terms of a key/lock‐type interaction. The results are compared with corresponding data for 2,2′‐dimethyl‐6,6′‐diphenyl‐4,4′‐bipyrimidine.

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“…So far, there have been great efforts to control the chemo-, regio-, and enantioselectivities of the reaction product. 9 An enantioselective copper-catalyzed allylic alkylation with Grignard and organozinc reagents was recently reported. 10 The products are obtained in very good yields and usually in high enantiomeric excess.…”

Section: (B) Stereoselective Formation Of Enamidesmentioning

confidence: 99%

Copper(I) Thiophene-2-carboxylate (CuTC)

Innitzer¹

2005

Synlett

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Nucleophilic and organometallic displacement reactions of allylic compounds: stereo-and regiochemistry

Cited by 380 publications

References 223 publications

Acetyl Coenzyme A:Salutaridinol-7-O-Acetyltransferase from Papaver somniferum Plant Cell Cultures:

Acetyl Coenzyme A:Salutaridinol-7-O-Acetyltransferase from Papaver somniferum Plant Cell Cultures:

Synthesis and Experimental Electron Density of Bis(heterocyclic) Azines: The Case of 6,6′-Bis(chloromethyl)-2,2′-bipyrazine

Copper(I) Thiophene-2-carboxylate (CuTC)

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