Highly Selective Hydrogenation of C═C Bonds Catalyzed by a Rhodium Hydride
作者:Yiting Gu、Jack R. Norton、Farbod Salahi、Vladislav G. Lisnyak、Zhiyao Zhou、Scott A. Snyder
DOI:10.1021/jacs.1c04683
日期:2021.6.30
Undermildconditions (room temperature, 80 psi of H2) Cp*Rh(2-(2-pyridyl)phenyl)H catalyzes the selectivehydrogenation of the C═C bond in α,β-unsaturated carbonyl compounds, including natural product precursors with bulky substituents in the β position and substrates possessing an array of additional functionalgroups. It also catalyzes the hydrogenation of many isolated double bonds. Mechanistic
在温和条件下(室温,80 psi H 2)Cp*Rh(2-(2-吡啶基)苯基)H催化α,β-不饱和羰基化合物(包括天然产物前体)中C=C键的选择性氢化在 β 位具有庞大的取代基,并且底物具有一系列额外的官能团。它还催化许多分离的双键的氢化。机理研究表明,不涉及自由基中间体,并且催化剂似乎是均相的,从而为类似氢化过程的现有方案提供了重要的互补性。
Strategy for Catalytic Chemoselective Cross-Enolate Coupling Reaction via a Transient Homocoupling Dimer
A new strategy, a transient homocoupling dimer strategy, for direct catalytic oxidative cross-enolate coupling reactions is developed. Cross-enolate coupling products bearing a (contiguous) tetrasubstituted carbon center were obtained chemoselectively without the need for stoichiometric amounts of strong bases/metal oxidants, and thus, the present catalysis provides a general method for the synthesis
N-Heterocyclic carbene (NHC) catalyzed chemoselective acylation of alcohols in the presence of amines with various acylating reagents
作者:Ramesh C. Samanta、Suman De Sarkar、Roland Fröhlich、Stefan Grimme、Armido Studer
DOI:10.1039/c3sc00099k
日期:——
subsequent acylation step. NHC-catalyzed selective acylation of benzyl alcohol in the presence of benzylamine can also be achieved with trifluoroethyl and hexafluoroisopropylesters as acylation reagents. Moreover, an enol acetate also shows high O-selectivity as a chemoselective acetylation reagent. Kinetic and mechanistic studies are provided and some examples of the chemoselectiveacylation of amino
Copper-catalyzed aerobic asymmetric cross-dehydrogenative coupling of C(sp<sup>3</sup>)–H bonds driven by visible light
作者:Kexu Zhou、Ying Yu、Yu-Mei Lin、Yanjun Li、Lei Gong
DOI:10.1039/d0gc00262c
日期:——
Asymmetric cross-dehydrogenative coupling (CDC) of C(sp3)–H bonds shows great potential for rapid and stereoselective construction of C–Cbonds and use of molecular oxygen as the oxidant for such transformations is appealing in the context of green synthetic methodologies. However, the poor reactivity of oxygen at the ground state and the challenges in controlling the stereochemistry make it extremely
Light‐Driven Enantioselective Synthesis of Pyrroline Derivatives by a Radical/Polar Cascade Reaction
作者:Ricardo I. Rodríguez、Leonardo Mollari、José Alemán
DOI:10.1002/anie.202013020
日期:2021.2.23
functionalization of acyl heterocycles through a hydrogen‐atom transfer (HAT) process and the use of tailor‐made ketimines as reliable electrophilic partners. This transformation is translated into an enantiomerically controlled radical/polar cascade reaction in which water is produced as the sole by‐product and stereoselectivity is dictated by coordination to a chiral‐at‐rhodium catalyst.