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Allylation Reaction (allylation + reaction)
Selected AbstractsChemInform Abstract: In(OTf)3 -Catalyzed Allylation Reaction of Imines with Tetraallyltin.CHEMINFORM, Issue 25 2009Xiao Ning Wei Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Metal-Mediated Diastereoselective Allylation Reaction of Chiral ,,,-Epoxy Aldehyde.CHEMINFORM, Issue 6 2009Part 2. Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Unexpected Effect of the Fluorine Atom on the Optimal Ligand-to-Palladium Ratio in the Enantioselective Pd-Catalyzed Allylation Reaction of Fluorinated Enol Carbonates.CHEMINFORM, Issue 47 2008Etienne Belanger Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Highly Efficient and Stereoselective Route to threo- and erythro-,-Allylated ,-Fluoro-,-hydroxy Esters via Radical Allylation Reaction.CHEMINFORM, Issue 33 2002Takashi Ishihara Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Use of Cyclic Allylic Bromides in the SnCl2/Cu-mediated Aqueous Carbonyl Allylation ReactionCHINESE JOURNAL OF CHEMISTRY, Issue 3 2005Tan Xiang-Hui Abstract Five- and six-membered cyclic allylic halides were found to be much less reactive than the acyclic allylic halides in aqueous allylation reactions. Nevertheless, it was found that SnCl2/Cu was powerful enough to mediate the aqueous allylation reactions involving cyclic allylic halides. Both the aliphatic and aromatic aldehydes could beefficiently allylated and the reaction condition was mild, simple and safe. The yields were usually in 75%,97% and the reaction was erythro selective. [source] ChemInform Abstract: Highly Diastereoselective Allylation Reactions of Dilithiated 4-(Phenylsulfonyl)-cyclopent-2-enol.CHEMINFORM, Issue 14 2010Donald Craig Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Palladium-Catalyzed Conjugate Allylation Reactions of ,,,-Unsaturated N-Acylpyrroles.CHEMINFORM, Issue 12 2009Michael B. Shaghafi Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Lewis Acid Promoted Tandem Intermolecular Diels,Alder/Intramolecular Allylation Reactions of Silyl-Substituted 1,3-Butadienes Leading to Multisubstituted 7-Norbornenones and Related Polycyclic Compounds.CHEMINFORM, Issue 21 2008Dongzhen Li Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Zinc-Mediated Allylation Reactions of Aldehydes and Ketones in Aqueous Media under Ultrasonic Irradiation.CHEMINFORM, Issue 41 2006Yan-Jiang Bian Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Allylation Reactions of Carbonyl Compounds Using an Organosilicon Reagent in Aqueous Media.CHEMINFORM, Issue 28 2003Naohiro Aoyama Abstract For Abstract see ChemInform Abstract in Full Text. [source] A One-Pot Synthesis of Doubly Unsaturated Trifluoromethyl Amines:Easy Access to CF3 -Substituted PiperidinesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 7 2005Guillaume Magueur Abstract A straightforward route to trifluoromethyl analogs of piperidines is described. These syntheses involve a Barbier-type allylation reaction of trifluoroacetaldimines, followed by N -allylation (one-pot), and ring-closing metathesis. An efficient asymmetric version is also reported (>98,% de). Functionalized heterobicyclic compounds can also be obtained by a Pauson,Khand reaction. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Importance of the Conditioning of the Chitosan Support in a Catalyst-Containing Ionic Liquid Phase Immobilised on Chitosan: The Palladium-Catalysed Allylation Reaction CaseADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2-3 2010Renaud Moucel Abstract Catalysts containing ionic liquid phase immobilised on chitosan are successfully applied to the palladium-catalysed allylation reaction. A strong influence of the conditioning of chitosan not only on the activity and enantioselectivity but also on the recyclability and reusability of the catalyst is demonstrated. [source] Bismuth Triflate-Catalyzed Addition of Allylsilanes to N -Alkoxycarbonylamino Sulfones: Convenient Access to 3-Cbz-Protected CyclohexenylaminesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2009Thierry Ollevier Abstract Bismuth triflate was found to be an efficient catalyst in the Sakurai reaction of allyltrimethylsilanes with N -alkoxycarbonylamino sulfones. The reaction proceeded smoothly with a low catalyst loading of Bi(OTf)3,4,H2O (2,5,mol%) to afford the corresponding protected homoallylic amines in very good yields (up to 96%). A sequential allylation reaction followed by ring-closing metathesis delivers 6,8 membered 3-Cbz-protected cycloalkenylamines. [source] Merging Organocatalysis with an Indium(III)-Mediated Process: A Stereoselective ,-Alkylation of Aldehydes with Allylic AlcoholsCHEMISTRY - A EUROPEAN JOURNAL, Issue 37 2010Montse Guiteras Capdevila Curiosity killed the CAT,ions! The use of stabilized cationic intermediates can be considered as a new frontier in the development of stereoselective reactions. An organocatalytic procedure mediated by the MacMillan imidazolidinone catalyst was coupled with an InBr3 -mediated process for the development of a novel stereoselective allylation reaction of aldehydes. Up to 98,% ee and up to 5:1 d.r. were obtained in the process. [source] Regio- and Stereoselective Palladium-Pincer Complex Catalyzed Allylation of Sulfonylimines with Trifluoro(allyl)borates and Allylstannanes: A Combined Experimental and Theoretical StudyCHEMISTRY - A EUROPEAN JOURNAL, Issue 26 2006Olov A. Wallner Dr. Abstract Regio- and stereoselective palladium-pincer complex catalyzed allylation of sulfonylimines has been performed by using substituted trifluoro(allyl)borates and trimethylallylstannanes. The reactions provide the corresponding branched allylic products with excellent regioselectivity. The stereoselectivity of these processes is very high when trifluoro(cinnamyl)borate and trimethyl cinnamyl stannane are employed as allylic precursors; however, the reaction with trifluoro(crotyl)borate results in poor stereoselectivity. The major diastereomer formed in these reactions was the syn isomer, while the (previously reported) reactions with aldehyde electrophiles afforded the anti products, indicating that the mechanism of the stereoselection is dependent on the applied electrophile. Therefore, we have studied the mechanistic aspects of the allylation reactions by experimental studies and DFT modeling. The experimental mechanistic studies have clearly shown that potassium trifluoro(allyl)borate undergoes transmetallation with palladium-pincer complex 1,a affording an ,1 -allylpalladium-pincer complex (1,e). The mechanism of the transfer of the allyl moiety from palladium to the sulfonylimine substrate was studied by DFT calculations at the B3PW91/LANL2DZ+P level of theory. These calculations have shown that the electrophilic substitution of sulfonylimines proceeds in a one-step process with a relatively low activation energy. The topology of the potential energy surface in the vicinity of the transition-state structure proved to be rather complicated as nine different geometries with similar energies were located as first order saddle points. Our studies have also shown that the high stereoselectivity with cinnamyl metal reagents stems from steric interactions in the TS structure of the allylation reaction. In addition, these studies have revealed that the mechanism of the stereoselection in the allylation of aldehydes and sulfonylimines is fundamentally different. [source] Synthesis of Aminophosphine Ligands with Binaphthyl Backbones for Silver(I)-catalyzed Enantioselective Allylation of Benzaldehyde,CHINESE JOURNAL OF CHEMISTRY, Issue 11 2002Yi Wang Abstract A series of aminophosphine ligands was synthesized from 2-amino-2,-hydroxy-1,1,-binaphthyl (NOBIN). Their asymmetric induction efficiency was examined for silver(I) catalyzed enantioselective allylation reaction of benzaldehyde with allyltributyltin. Under the optimized reaction conditions, quantitative yield as well as moderate ee value (54.5% ee) of product was achieved by the catalysis with silver(I)/3 complex. The effects of the binaphthyl backbone and the substitutes situated at chelating N, P atoms on enantioselectivity of the reaction were also discussed. [source] Stereoselective Synthesis of the Naturally Occurring 2-Pyranone DodoneineEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 23 2008Paula Álvarez-Bercedo Abstract The first total synthesis of the naturally occurring dihydropyranone dodoneine is reported. Asymmetric allylation reactions were used for the stereoselective generation of the two stereogenic centers. The pyranone ring was created by ring-closing metathesis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] The Total Synthesis and Biological Properties of the Cytotoxic Macrolide FD-891 and Its Non-Natural (Z)-C12 IsomerCHEMISTRY - A EUROPEAN JOURNAL, Issue 18 2007Jorge García-Fortanet Dr. Abstract A total, stereoselective synthesis of the naturally occurring, cytotoxic macrolide FD-891 and of its non-natural (Z)-C12 isomer is described. Three fragments of the main carbon chain were stereoselectively prepared by using asymmetric aldol and allylation reactions as the key steps. The molecule was then assembled by using two Julia,Kocienski olefinations to connect the three fragments and a Yamaguchi reaction to close the macrolactone ring. Some specific biological properties (cytotoxicity, binding to tubulin) have been determined for both macrolides. The E configuration of the C12,C13 olefinic bond seems to be an important feature in determining the cytotoxicity but the precise biological mechanism of the latter still remains to be cleared. [source] Regio- and Stereoselective Palladium-Pincer Complex Catalyzed Allylation of Sulfonylimines with Trifluoro(allyl)borates and Allylstannanes: A Combined Experimental and Theoretical StudyCHEMISTRY - A EUROPEAN JOURNAL, Issue 26 2006Olov A. Wallner Dr. Abstract Regio- and stereoselective palladium-pincer complex catalyzed allylation of sulfonylimines has been performed by using substituted trifluoro(allyl)borates and trimethylallylstannanes. The reactions provide the corresponding branched allylic products with excellent regioselectivity. The stereoselectivity of these processes is very high when trifluoro(cinnamyl)borate and trimethyl cinnamyl stannane are employed as allylic precursors; however, the reaction with trifluoro(crotyl)borate results in poor stereoselectivity. The major diastereomer formed in these reactions was the syn isomer, while the (previously reported) reactions with aldehyde electrophiles afforded the anti products, indicating that the mechanism of the stereoselection is dependent on the applied electrophile. Therefore, we have studied the mechanistic aspects of the allylation reactions by experimental studies and DFT modeling. The experimental mechanistic studies have clearly shown that potassium trifluoro(allyl)borate undergoes transmetallation with palladium-pincer complex 1,a affording an ,1 -allylpalladium-pincer complex (1,e). The mechanism of the transfer of the allyl moiety from palladium to the sulfonylimine substrate was studied by DFT calculations at the B3PW91/LANL2DZ+P level of theory. These calculations have shown that the electrophilic substitution of sulfonylimines proceeds in a one-step process with a relatively low activation energy. The topology of the potential energy surface in the vicinity of the transition-state structure proved to be rather complicated as nine different geometries with similar energies were located as first order saddle points. Our studies have also shown that the high stereoselectivity with cinnamyl metal reagents stems from steric interactions in the TS structure of the allylation reaction. In addition, these studies have revealed that the mechanism of the stereoselection in the allylation of aldehydes and sulfonylimines is fundamentally different. [source] Use of Cyclic Allylic Bromides in the SnCl2/Cu-mediated Aqueous Carbonyl Allylation ReactionCHINESE JOURNAL OF CHEMISTRY, Issue 3 2005Tan Xiang-Hui Abstract Five- and six-membered cyclic allylic halides were found to be much less reactive than the acyclic allylic halides in aqueous allylation reactions. Nevertheless, it was found that SnCl2/Cu was powerful enough to mediate the aqueous allylation reactions involving cyclic allylic halides. Both the aliphatic and aromatic aldehydes could beefficiently allylated and the reaction condition was mild, simple and safe. The yields were usually in 75%,97% and the reaction was erythro selective. [source] | ||||||||||||||||||||||