10473-14-0Relevant articles and documents
Highly efficient continuous flow reactions using singlet oxygen as a "Green" reagent
Levesque, Francois,Seeberger, Peter H.
, p. 5008 - 5011 (2011)
Described is a new method for the efficient in situ production of singlet oxygen in a simple continuous flow photochemical reactor. The extremely large interfacial area generated by running the biphasic mixture in a narrow channel at a high flow rate ensures high throughput as well as fast and efficient oxidation of various alkenes, 1,3-dienes, and thioethers on a preparative scale.
Ruthenium-lewis acid catalyzed asymmetric diels-alder reactions between dienes and α,β-unsaturated ketones
Rickerby, Jenny,Vallet, Martial,Bernardinelli, Gerald,Viton, Florian,Kuendig, E. Peter
, p. 3354 - 3368 (2007)
The complex [Ru(Cp)(R,R-BIPHOP-F)(acetone)][SbF6],(R,R)-1a. was used as catalyst for asymmetric Diels-Alder reactions between dienes (cyclopentadiene, methylcyclopentadienc, isoprene, 2,3-dimethylbutadiene) and α,β-unsaturated ketones (methyl vinyl ketone (MVK). ethyl vinyl ketone, divinyl ketone, α-bromovinyl methyl ketone and α-chlorovinyl methyl ketone). The cycloaddition products were obtained in yields of 50-_90% and with enantioselectivities up to 96% ee. Ethyl vinyl ketone, divinyl ketone and the halogenated vinyl ketones worked best and their reactions with acyclic dienes consistently provided products with >90% ee. α-Chlorovinyl methyl ketone performed better than α-bromovinyl methyl ketone. The reaction also provided a [4.3.1]bicyclic ring system in 95% ee through an intramolecular cycloaddition reaction. Crystal structure determinations of [Ru(Cp)((S,S)-BIPHOP-F)(mvk)]-[SbF6], (S,S)-1b, and [Ru(Cp)((R,R)-Me4BIPHOP-F)(acrolein)][SbF6], (R,R)-2b, provided the basis for a rationalization of the asymmetric induction.
Highly Diastereoselective Synthesis of Substituted Epichlorohydrins and Regioselective Preparation of Allyl Alcohols using Chloro or Idomethyllithium
Concellon, Jose M.,Llavona, Lujan,Bernad, Pablo L. Jr.
, p. 5573 - 5584 (1995)
Substituted epichlorohydrins 3 or 6 are obtained α-bromo or α-chlorocarbonyl compounds (1 or 4) and chloro or iodomethyllithium, respectively.Starting from α-bromocarbonyl compounds 1 or acyclic α-chloro ketones the reaction takes place with total diastereoselectivity.Treatment of epichlorohydrins 3 or 6 with lithium iodide affords the same substituted allyl alcohols 7 in a regioselective manner.A mechanism to explain this transformation is proposed.Regioisomeric allyl alcohols 11 are prepared by reaction of epichlorohydrins 6 with lithium powder.
Preparation of disubstituted epichlorohydrins with total diastereoselectivity. Transformation of α-bromocarbonyl compounds into allyl alcohols
Barluenga, Jose,Llavona, Lujan,Bernad, Pablo L.,Concellon, Jose M.
, p. 3173 - 3176 (1993)
Epichlorohydrins 3 have been obtained with total diastereoselectivity from α-bromocarbonyl compounds and chloromethyllithium generated in situ. The treatment of compounds 3 with lithium iodide or lithium powder affords allyl alcohols 4 in a regioselective manner.
Novel conversion of 1,2-disubstituted cis-epoxides to one-carbon homologated allylic alcohols using dimethylsulfonium methylide
Alcaraz, Lilian,Cridland, Andrew,Kinchin, Elizabeth
, p. 4051 - 4053 (2001)
matrix presented The treatment of cis-epoxides with an excess of dimethylsulfonium methylide affords one-carbon homologated allylic alcohols in good to excellent yields.
SYNTHESIS OF 2-SUBSTITUTED 1,3-BUTADIENYL COMPOUNDS BY PALLADIUM-CATALYZED REGIOSELECTIVE 1,2-ELIMINATION REACTION OF METHYLVINYLCARBINOL ACETATES
Carpita, Adriano,Bonaccorsi, Fabrizio,Rossi, Renzo
, p. 5193 - 5196 (1984)
Alkylation of the dianion of 3-methyl-3-buten-2-ol, followed by acetylation and palladium-catalyzed 1,2-elimination reaction of the so obtained methylvinylcarbinol acetates allows to synthesize regioselectively 2-substituted 1,3-butadienyl compounds having high isomeric purity.
TRICYCLIC HETEROCYCLE COMPOUNDS USEFUL AS HIV INTEGRASE INHIBITORS
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Page/Page column 75, (2019/11/12)
The present invention relates to Tricyclic Heterocycle Compounds of Formula (I): (I) and pharmaceutically acceptable salts or prodrug thereof, wherein R1, R2, R3, R4, R5, R6 and n are as defined herein. The present invention also relates to compositions comprising at least one Tricyclic Heterocycle Compound, and methods of using the Tricyclic Heterocycle Compounds for treating or preventing HIV infection in a subject.
Self-assembled benzophenone bis-urea macrocycles facilitate selective oxidations by singlet oxygen
Geer, Michael F.,Walla, Michael D.,Solntsev, Kyril M.,Strassert, Cristian A.,Shimizu, Linda S.
, p. 5568 - 5578 (2013/07/26)
This manuscript investigates how incorporation of benzophenone, a well-known triplet sensitizer, within a bis-urea macrocycle, which self-assembles into a columnar host, influences its photophysical properties and affects the reactivity of bound guest molecules. We further report the generation of a remarkably stable organic radical. As expected, UV irradiation of the host suspended in oxygenated solvents efficiently generates singlet oxygen similar to the parent benzophenone. In addition, this host can bind guests such as 2-methyl-2-butene and cumene to form stable solid host-guest complexes. Subsequent UV irradiation of these complexes facilitated the selective oxidation of 2-methyl-2-butene into the allylic alcohol, 3-methyl-2-buten-1-ol, at 90% selectivity as well as the selective reaction of cumene to the tertiary alcohol, α,α′-dimethyl benzyl alcohol, at 63% selectivity. However, these products usually arise through radical pathways and are not observed in the presence of benzophenone in solution. In contrast, typical reactions with benzophenone result in the formation of the reactive singlet oxygen that reacts with alkenes to form endoperoxides, diooxetanes, or hydroperoxides, which are not observed in our system. Our results suggest that the confinement, the formation of a stable radical species, and the singlet oxygen photoproduction are responsible for the selective oxidation processes. A greater understanding of the mechanism of this selective oxidation could lead to development of greener oxidants.
Ionic liquids for enhancing the enantioselectivity of isolated BVMO-catalysed oxidations
Rodriguez, Cristina,De Gonzalo, Gonzalo,Fraaije, Marco W.,Gotor, Vicente
experimental part, p. 2255 - 2260 (2011/02/24)
The present study describes the first-time usage of an isolated thermostable Baeyer-Villiger monooxygenase (phenylacetone monooxygenase, PAMO) in the presence of ionic liquids. The stability, activity and selectivity of PAMO as an oxidative enzyme in the presence of different ionic liquids were studied. This revealed that the addition of some specific ionic liquids, such Ammoeng 102 and [bmim]MeSO4, can significantly enhance the E-value in the oxidation of racemic benzylketones. Moreover, the use of ionic liquids increases the optimal substrate concentration for performing Baeyer-Villiger oxidation, thereby extending the biocatalytic repertoire of PAMO for synthetic applications.
Baeyer-Villiger monooxygenase-catalyzed kinetic resolution of racemic α-alkyl benzyl ketones: enzymatic synthesis of α-alkyl benzylketones and α-alkyl benzylesters
Rodriguez, Cristina,Gonzalo, Gonzalo de,Torres Pazmino, Daniel E.,Fraaije, Marco W.,Gotor, Vicente
experimental part, p. 1168 - 1173 (2009/10/02)
The application of three BVMOs for the enantioselective oxidation of 3-phenylbutan-2-ones with different substituents in the aromatic moiety is described. By choosing the appropriate biocatalyst and substrate combination, chiral ketones and esters can be obtained with excellent enantiopurities. This methodology could also be applied to the resolution of racemic α-alkyl benzylketones with longer alkyl chains as well as with two substituted α-substituted benzylacetones. A kinetic analysis revealed that the BVMOs studied effectively convert all tested compounds showing that the enzymes are tolerant towards the substrate structure while being highly enantioselective. These properties render BVMOs as valuable biocatalysts for the preparation of compounds with high interest in organic synthesis.
