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Alkenylboronic Acids (alkenylboronic + acid)
Selected AbstractsChemInform Abstract: Stereoselective Conjugate Addition of Aryl- and Alkenylboronic Acids to Acyclic ,,,-Oxygen-Substituted ,,,-Enoates.CHEMINFORM, Issue 4 2008Amaya Segura 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] Rhodium-Catalyzed Asymmetric Addition of Aryl- and Alkenylboronic Acids to Isatins.CHEMINFORM, Issue 37 2006Ryo Shintani 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] t-Bu-Amphos,RhCl3×3H2O: A Highly Recyclable Catalyst System for the Cross-Coupling of Aldehydes and Aryl- and Alkenylboronic Acids in Aqueous Solvents.CHEMINFORM, Issue 4 2006Rongcai Huang Abstract For Abstract see ChemInform Abstract in Full Text. [source] Stereoselectivity Control in the Rh(I)-Catalyzed Conjugate Additions of Aryl and Alkenylboronic Acids to Unprotected Hydroxycyclopentenones.CHEMINFORM, Issue 37 2005Gabriela de la Herran Abstract For Abstract see ChemInform Abstract in Full Text. [source] Suzuki Cross-Coupling Reactions Between Alkenylboronic Acids and Aryl Bromides Catalyzed by a Tetraphosphane-Palladium Catalyst.CHEMINFORM, Issue 26 2004Eugenie Peyroux Abstract For Abstract see ChemInform Abstract in Full Text. [source] Nickel-Catalyzed Mizoroki,Heck- versus Michael-Type Addition of Organoboronic Acids to ,,,-Unsaturated Alkenes through Fine-Tuning of LigandsCHEMISTRY - AN ASIAN JOURNAL, Issue 11 2007Pao-Shun Lin Abstract Various arylboronic acids reacted with activated alkenes in the presence of [Ni(dppe)Br2], ZnCl2, and H2O in CH3CN at 80,°C to give the corresponding Mizoroki,Heck-type addition products in good to excellent yields. Furthermore, 1,equivalent of the hydrogenation product of the activated alkene was also produced. By tuning the ligands of the nickel complexes and the reaction conditions, Michael-type addition was achieved in a very selective manner. Thus, various p- and o- substituted arylboronic acids or alkenylboronic acid reacted smoothly with activated alkenes in CH3CN at 80,°C for 12,h catalyzed by Ni(acac)2, P(o -anisyl)3, and K2CO3 to give the corresponding Michael-type addition products in excellent yields. However, for m- substituted arylboronic acids, the yields of Michael-type addition products are very low. The cause of this unusual meta -substitution effect is not clear. By altering the solvent or phosphine ligand, the product yields for m- substituted arylboronic acids were greatly improved. In contrast to previous results in the literature, the present catalytic reactions required water for Mizoroki,Heck-type products and dry reaction conditions for Michael-type addition products. Possible mechanistic pathways for both addition reactions are proposed. [source] Coupling reaction of organoboronic acids with chloropyrimidines and trichlorotriazine,CHINESE JOURNAL OF CHEMISTRY, Issue 9 2004Jiu-Qing Tan Abstract Pd-catalyzed cross-coupling reactions of chloropyrimidines with alkenylboronic acids readily proceed to give the corresponding alkenylpyrimidines in high to excellent yields. The coupling reaction of 2,4-dichloropyrimidine or 2,4,6-trichloropyrimidine with one equivalent of alkenylboronic acid occurred more easily on 4-position than on 2-position, which implied that the reaction is highly regioselective. The reaction is stereospecific since the configuration of C=C remained intact. The preliminary study on the cross-coupling reactions of 2,4,6-trichlorotriazine with one equivalent of arylboronic acids showed that the reactions afforded the monosubstituted triazines in moderate yields. The effect of steric hindrance of the substitutents on the reactions was found. [source] ChemInform Abstract: Rhodium-Catalyzed Chemo- and Stereoselective Arylative and Alkenylative Cyclization Reactions of Unsymmetric Diynes Containing a Terminal Alkyne Moiety with Organoboronic Acids.CHEMINFORM, Issue 38 2010Levent Artok Abstract A variety of 1,6-diynes containing a terminal alkyne, e.g. (I) or (IV), reacts with aryl- (II) or alkenylboronic acids (VI) with excellent chemo- and stereoselectivity in the presence of a Rh2(cod)2(O-Me)2 complex to give the 5-exo cyclization products, exclusively. [source] Coupling reaction of organoboronic acids with chloropyrimidines and trichlorotriazine,CHINESE JOURNAL OF CHEMISTRY, Issue 9 2004Jiu-Qing Tan Abstract Pd-catalyzed cross-coupling reactions of chloropyrimidines with alkenylboronic acids readily proceed to give the corresponding alkenylpyrimidines in high to excellent yields. The coupling reaction of 2,4-dichloropyrimidine or 2,4,6-trichloropyrimidine with one equivalent of alkenylboronic acid occurred more easily on 4-position than on 2-position, which implied that the reaction is highly regioselective. The reaction is stereospecific since the configuration of C=C remained intact. The preliminary study on the cross-coupling reactions of 2,4,6-trichlorotriazine with one equivalent of arylboronic acids showed that the reactions afforded the monosubstituted triazines in moderate yields. The effect of steric hindrance of the substitutents on the reactions was found. [source] | ||||||||||