26929-46-4Relevant academic research and scientific papers
Organocatalytic Trapping of Elusive Carbon Dioxide Based Heterocycles by a Kinetically Controlled Cascade Process
Bo, Carles,Kleij, Arjan W.,Limburg, Bart,Qiao, Chang,Sprachmann, Josefine,Villar-Yanez, Alba
supporting information, p. 18446 - 18451 (2020/08/21)
A conceptually novel approach is described for the synthesis of six-membered cyclic carbonates derived from carbon dioxide. The approach utilizes homoallylic precursors that are converted into five-membered cyclic carbonates having a β-positioned alcohol group in one of the ring substituents. The activation of the pendent alcohol group through an N-heterocyclic base allows equilibration towards a thermodynamically disfavored six-membered carbonate analogue that can be trapped by an acylating agent. Various control experiments and computational analysis of this manifold are in line with a process that is primarily dictated by a kinetically controlled acylation step. This cascade process delivers an ample diversity of six-membered cyclic carbonates in excellent yields and chemoselectivities under mild reaction conditions.
Development of Enantioselective Palladium-Catalyzed Alkene Carboalkoxylation Reactions for the Synthesis of Tetrahydrofurans
Hopkins, Brett A.,Garlets, Zachary J.,Wolfe, John P.
supporting information, p. 13390 - 13392 (2015/11/09)
The Pd-catalyzed coupling of γ-hydroxyalkenes with aryl bromides affords enantiomerically enriched 2-(arylmethyl)tetrahydrofuran derivatives in good yield and up to 96:4 e.r. This transformation was achieved through the development of a new TADDOL/2-arylcyclohexanol-derived chiral phosphite ligand. The transformations are effective with an array of different aryl bromides, and can be used for the preparation of products bearing quaternary stereocenters.
LITHIUM-POROUS METAL OXIDE COMPOSITIONS AND LITHIUM REAGENT-POROUS METAL COMPOSITIONS
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Paragraph 0059; 0060; 0061, (2014/10/29)
The invention relates to lithium reagent-porous metal oxide compositions having RLi absorbed into a porous oxide. In formula RLi, R is an alkyl group, an alkenyl group, an alkyny group, an aryl group, an alkaryl group, or an NR1R2 group; R1 is an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkaryl group; and R2 is hydrogen, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, and an alkaryl group. The preparation and use of lithium reagent-porous metal oxide compositions having RLi absorbed into a porous oxide compositions are also described.
Zinc(ii)-catalyzed Grignard additions to ketones with RMgBr and RMgI
Hatano, Manabu,Ito, Orie,Suzuki, Shinji,Ishihara, Kazuaki
scheme or table, p. 2674 - 2676 (2010/07/08)
Highly efficient alkylations and arylations of ketones with Grignard reagents (RMgBr and RMgI) have been developed using catalytic ZnCl2, Me3SiCH2MgCl, and LiCl. Tertiary alcohols were obtained in high yields with high chemoselectivities, while minimizing undesired side products produced by reduction and enolization.
Zinc(II)-catalyzed addition of grignard reagents to ketones
Hatano, Manabu,Ito, Orie,Suzuki, Shinji,Ishihara, Kazuaki
supporting information; experimental part, p. 5008 - 5016 (2010/10/04)
(Figure presented) The addition of organometallic reagents to carbonyl compounds has become a versatile method for synthesizing tertiary and secondary alcohols via carbon-carbon bond formation. However, due to the lack of good nucleophilicity or the presence of strong basicity of organometallic reagents, the efficient synthesis of tertiary alcohols from ketones has been particularly difficult and, thus, limited. We recently developed highly efficient catalytic alkylation and arylation reactions to ketones with Grignard reagents (RMgX: R = alkyl, aryl; X = Cl, Br, I) using ZnCl2, Me3SiCH 2MgCl, and LiCl, which effectively minimize problematic side reactions. In principle, RMgBr and RMgI are less reactive than RMgCl for the addition to carbonyl compounds. Therefore, this novel method with homogeneous catalytic ZnCl2·Me3SiCH2MgCl·LiCl is quite attractive, since RMgBr and RMgI, which are easily prepared and/or commercially available, like RMgCl, can be applied successfully. As well as ketones and aldehydes, aldimines were effectively applied to this catalysis, and the corresponding secondary amines were obtained in high yield. With regard to mechanistic details concerning β-silyl effect and salt effect, in situ-prepared [R(Me3SiCH2)2Zn] -[Li]+[MgX2]m[LiCl]n (X = Cl/Br/I) is speculated to be a key catalytic reagent to promote the reaction effectively. The simplicity of this reliable ZnCl2·Me 3SiCH2MgCl·LiCl system in the addition of Grignard reagents to carbonyl compounds might be attractive for industrial as well as academic applications.
CHLOROMETHYL-LITHIUM AND 1-CHLORO-2-METHYLPROP-1-ENYL-LITHIUM: USEFUL INTERMEDIATES IN THE SYNTHESIS OF UNSATURATED AND BIFUNCTIONALIZED COMPOUNDS
Barluenga, Jose,Fernandez-Simon, Jose L.,Concellon, Jose M.,Yus, Miguel
, p. 3339 - 3344 (2007/10/02)
The reaction of in situ generated chloromethyl-lithium with ketones (5) at -78 deg C afforded, after lithiation with lithium naphthalenide at the same temperature, β-oxidoalkyl-lithium compounds (6), which on reaction with electrophiles (deuterium oxide, dimethyl disulphide, carbon dioxide, cyclohexanone, and allyl bromide) yielded bifunctionalized compounds (7).When the lithiation step was carried out with lithium powder and at temperatures ranging between -60 deg C and 20 deg C, the corresponding decomposition of intermediates (6) derived from aldehydes and ketones (5) took place spontaneously giving the corresponding terminal or exocyclic olefins (11) regioselectively.The use of in situ generated 1-chloro-2-methylprop-1-enyl-lithium as organolithium reagent in the addition to carbonyl compounds (5) at -110 deg C, followed by transformation of the resulting chlorohydrin (13) into the corresponding methyl ether (14) (successive treatment with sodium hydride and methyl iodide at 0-20 deg C) gave, after lithiation with lithium phenanthrenide at room temperature, the corresponding substituted cumulenes (12).
β-Oxidofunctionalized Organolithium Intermediates from Ketones: A Simple New Access
Barluenga, Jose,Fernandez-Simon, Jose L.,Concellon, Jose M.,Yus, Miguel
, p. 915 - 916 (2007/10/02)
Chloromethyl-lithium generated in situ, reacts at -78 deg C with ketones (5) to afford, after lithiation with lithium naphthalenide, β-oxidoalkyl-lithium compounds (1), which on reaction with electrophiles (deuterium oxide, dimethyl disulphide, carbon dioxide, cyclohexanone, and allyl bromide) yield bifunctionalized compounds (6).
