该手稿描述了使用先前描述的双功能钌基PC(sp 3)P络合物,20 mol%的甲酸钠和接近化学计量的甲酸进行内部炔烃E选择性转移半氢化的有效方案。末端炔烃的半氢化导致形成相应的苯乙烯。该反应的机理包括将氢化物和甲酸的质子逐步转移到底物上。这一事实允许通过简单地施加甲酸/甲酸钠/ D 2来开发用于合成单氘代烯烃的简便方案。以O混合物为氢源。通常已经实现了高产率,选择性和官能团相容性。
A novel, efficient Z-alkene synthesis via photocatalyzed decarboxylative couplings between terminal aryl alkynes and alkyl N-hydroxyphthalimide (NHPI) esters, which are derived from aliphatic carboxylic acids, is described. A wide range of primary, secondary, and tertiary carboxylates as well as α-amino acid and α-oxyacid-derived esters were employed as suitable substrates. The mild reaction conditions
as ligands for PdII-promoted organic reactions are reported for the first time. These ligands were utilized as catalytic sites and integrated into the skeleton of conjugated microporous polymers. By employing these CMP materials as selective regulators, oxidative Heck reactions between arylboronic esters and electronically unbiased alkenes provide highlyselective linear products.
catalytic ligand for the PdII-catalyzed oxidative Heck reaction with high linear selectivity. The linear selectivity of CMP-1 is about 30 times higher than that of bipyridine-based monomer ligand. This work opens a new front of using CMP as an intriguing platform for developing highly efficient catalysts in controlling the regioselectivity in organic reactions.
Studies on the 1,2-Migrations in Pd-Catalyzed Negishi Couplings with JosiPhos Ligands
作者:Anders T. Lindhardt、Thomas M. Gøgsig、Troels Skrydstrup
DOI:10.1021/jo801824e
日期:2009.1.2
cross-coupling, which is promoted by palladium catalyst systems generated with JosiPhos ligands. Several of the factors that were demonstrated to be important for the 1,2-migration include (1) the nucleophilicity of the organometallic reagent, which possibly influences the transmetalation step in direct competition with the intermediate β-hydride elimination of the alkenyl Pd(II) species; (2) the structural
Organophotocatalytic Radical–Polar Cross-Coupling of Styrylboronic Acids and Redox-Active Esters
作者:Allan J. B. Watson、Jeremy Brals、Nicholas D’Arcy-Evans、Thomas M. McGuire
DOI:10.1055/a-2179-6570
日期:2024.1
We report the development of a radical–polar cross-coupling reaction using styrylboronic acids and redox-active esters under organophotoredox catalysis. The reaction proceeds through a formal polarity-mismatched radical addition. The use of an organic photocatalyst permitted very low loadings of the electron-shuttle additive and accelerated reaction times compared with established processes. The scope