18272-91-8Relevant academic research and scientific papers
Palladium-catalyzed prenylation of (hetero)aryl boronic acids
Leister, Jeffrey,Chao, Darrian,Billingsley, Kelvin L.
supporting information, (2021/02/09)
Prenyl or dimethylallyl groups are common structural motifs in natural products and small molecule therapeutics. In this report, we describe a palladium-catalyzed method for the cross-coupling of aryl and heteroaryl boronic acids with prenyl alcohol. Catalyst systems based on dialkylbiaryl phosphines were highly active for this transformation. These supporting ligands provided opportunities for tuning the efficiency and regioselectivity of carbon–carbon bond formation. In addition, this method was further extended to the cross-coupling of symmetrical allylic alcohols with aryl boronic acids.
Synthesis of Tetrahydroisoindolinones via a Metal-Free Dehydrogenative Diels-Alder Reaction
Xu, Wen-Lei,Tang, Lei,Ge, Chen-Yu,Chen, Jie,Zhou, Ling
supporting information, p. 2268 - 2273 (2019/04/10)
A metal-free dehydrogenative Diels-Alder reaction of substituted alkenes for the synthesis of tetrahydroisoindolinones has been exploited for the first time. This new method features functional group tolerance and broad substrate scope, providing an efficient access to biologically active tetrahydroisoindolinone skeletons with endo steroselectivity in good to excellent yields. (Figure presented.).
Metal-Free Dehydrogenative Diels-Alder Reactions of Prenyl Derivatives with Dienophiles via a Thermal Reversible Process
Xu, Wen-Lei,Zhang, Heng,Hu, Yu-Long,Yang, Hui,Chen, Jie,Zhou, Ling
supporting information, p. 5774 - 5778 (2018/09/21)
An efficient dehydrogenative Diels-Alder reaction of prenyl derivatives with dienophiles has been developed. The reaction exhibits broad substrate scope and provides efficient access to cyclohexene derivatives with good to excellent yields. A reasonable mechanism involving a metal-free thermal reversible process is proposed.
ORGANOZINC REAGENTS AND PROCESSES FOR PREPARING AND USING THE SAME
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Page/Page column 35; 39; 41, (2016/10/04)
Provided is an organozinc composition comprising (a) an organozinc complex carrying an allylic ligand, (b) a magnesium component and (c) a lithium component. The organozinc composition is useful as a synthetic intermediate with excellent reactivity and selectivity, and can be stored for extended periods of time without loss of activity. Moreover, a process for the preparation of the organozinc composition and synthetic procedures making use of the organozinc composition are provided.
Nickel-Catalyzed Regioselective Reductive Cross-Coupling of Aryl Halides with Polysubstituted Allyl Halides in the Presence of Imidazolium Salts
Zhang, Zhan,Xu, Lijun,Chen, Zhengkai,Liu, Zhubo,Miao, Maozhong,Song, Jinyu,Ren, Hongjun
, p. 2784 - 2788 (2015/12/18)
The nickel-catalyzed direct reductive cross-coupling of aryl halides with readily accessible polysubstituted allyl halides provides an efficient method for preparing diverse allylated arenes under mild conditions. Both allyl bromides and allyl chlorides are compatible with the transformation.
Preparation of Solid, Substituted Allylic Zinc Reagents and Their Reactions with Electrophiles
Ellwart, Mario,Knochel, Paul
supporting information, p. 10662 - 10665 (2015/09/02)
The treatment of various allylic chlorides or bromides with zinc dust in the presence of lithium chloride and magnesium pivalate (Mg(OCOtBu)2) in THF affords allylic zinc reagents which, after evaporation of the solvent, produce solid zinc reagents that display excellent thermal stability. These allylic reagents undergo Pd-catalyzed cross-coupling reactions with PEPPSI-IPent, as well as highly regioselective and diastereoselective additions to aryl ketones and aldehydes. Acylation with various acid chlorides regioselectively produces the corresponding homoallylic ketones, with the new C-C bond always being formed on the most hindered carbon of the allylic system.
Regioselective cross-coupling of allylboronic acid pinacol ester derivatives with aryl halides via Pd-PEPPSI-IPent
Farmer, Jennifer L.,Hunter, Howard N.,Organ, Michael G.
supporting information, p. 17470 - 17473 (2013/01/15)
The cross-coupling reactions of allylboronic acid pinacol ester derivatives with aryl and heteroaryl halides occurred with high selectivity (>97%) at the α-carbon of the allylboron reagent in the presence of Pd-PEPPSI-IPent precatalyst and 5 M KOH in refluxing THF. In the case of trisubstituted allylboronates with different substituents on the olefin, minor olefin geometry isomerization was observed (E/Z & 80/20).
Studies on the intramolecular electron transfer catalyzed thermolysis of 1,2-dioxetanes
Nery, Ana L. P.,Wei?, Dieter,Catalani, Luiz H.,Baader, Wilhelm J.
, p. 5317 - 5327 (2007/10/03)
This work reports the synthesis and the chemiluminescence properties of the dioxetanes: 4-ethyl-4-methyl-3-(3-methoxyphenyl)-1,2-dioxetane (I), 4-ethyl-4-methyl-3-(3-tert-butyldimethylsilyloxyphenyl)-1,2-dioxetane (II), 4,4-dimethyl-3-(3-methoxybenzyl)-1,2-dioxetane (III) and 4,4-dimethyl-3-(3-tert-butyldimethylsilyloxybenzyl)-1,2-dioxetane (IV). While in the thermal decomposition of I-IV preferential formation of triplet excited states is observed, in the presence of fluoride ions the decomposition rate constants of II and IV increase drastically and singlet excited states are formed with high quantum yields. These results are discussed based on the CIEEL ('Chemically Initiated Electron Exchange Luminescence') mechanism where the decomposition of the dioxetanes should be initiated by an intramolecular electron transfer from the phenolate ion (generated by fluoride catalyzed deprotection of the silyloxy group), either directly bound to the peroxidic ring (II) or separated from it by a methylene bridge (IV). (C) 2000 Elsevier Science Ltd.
Arylcyclopropane Photochemistry. Substituent Effects on the Photochemical 1,3-Hydrogen Migration of 1,1-Dimethyl-2-phenylcyclopropane
Hixson, Stephen S.,Gallucci, Charles R.
, p. 2711 - 2713 (2007/10/02)
Irradiation of 1,1-dimethyl-2-arylcyclopropanes 1a-g (Ar = p-CF3C6H4 (1a), m-CF3C6H4 (1b), p-CH3C6H4 (1c), m-CH3C6H4 (1d), C6H5 (1e), m-OCH3C6H4 (1f), p-OCH3C6H4 (1g) gave in every case a 2-methyl-4-aryl-1-butene (2a-g) via a 1,3-hydrogen migration, accompanied by lesser amounts of a 3-methyl-1-aryl-2-butene (3a-g).Rearrangement is a singlet-state process.Rate constants for rearrangement were determined from reactant fluorescence lifetimes and product quantum yields.The rates for rearrangament of 1 to 2 were as follows:1a, 25*106s-1; 1b,15*106s-1; 1c, 7.9*106s-1; 1d, 6.1*106s-1; 1e, 2.3*106s-1; 1f, 1.9*106s-1; 1g, 0.87*106s-1.It isconcluded that the energetics of cyclopropane ring opening are important in the rate-determining step of the reaction.
Reactivity of Aryl Vinyl Di-?-methane Systems. Mechanistic and Exploratory Organic Photochemistry
Zimmerman, Howard E.,Swafford, Richard L.
, p. 3069 - 3083 (2007/10/02)
The di-?-methane rearrangement of a series of meta and para substituted arylvinylmethane reactants was investigated with the aim of determiningthe patterns of reactivity in systems in which initial excitation is localized in the aryl moiety.Thus the photo
