Search

Herein, we report an unprecedented copper‐catalyzed highly enantio‐ and diastereoselective radical oxyboration of β‐substituted styrenes. The lynchpin of success is ascribed to the development of a late‐stage stereomutation strategy, which enables enantioenriched cis‐isomers among a couple of early‐generated diastereomers to be converted into trans‐isomer counterparts, thus fulfilling high diastereocontrol; while the degree of enantio‐differentiation is determined by the borocupration process of the C=C bond. This reaction provides an efficient protocol to access enantioenriched trans‐1,2‐ dioxygenation products. The value of this method has further been highlighted in a diversity of follow‐up stereospecific transformations and further modifying complex molecules. [ABSTRACT FROM AUTHOR]

Herein, we report an unprecedented copper‐catalyzed highly enantio‐ and diastereoselective radical oxyboration of β‐substituted styrenes. The lynchpin of success is ascribed to the development of a late‐stage stereomutation strategy, which enables enantioenriched cis‐isomers among a couple of early‐generated diastereomers to be converted into trans‐isomer counterparts, thus fulfilling high diastereocontrol; while the degree of enantio‐differentiation is determined by the borocupration process of the C=C bond. This reaction provides an efficient protocol to access enantioenriched trans‐1,2‐ dioxygenation products. The value of this method has further been highlighted in a diversity of follow‐up stereospecific transformations and further modifying complex molecules. [ABSTRACT FROM AUTHOR]

The asymmetric hydrogenolysis of racemic 3-substitued-3-hydroxyisoindolin-1-ones has been developed employing SPINOL-derived phosphoric acid and a high steric demand Hantzsch ester as the hydrogen source. The corresponding products are obtained in good yields and up to 93% enantioselectivities. [ABSTRACT FROM AUTHOR]

A rhodium(II)/chiral phosphoric acid system has been developed for the asymmetric catalytic insertion of α-diazo esters into the O-H bond of carboxylic acids to generate an array of synthetically useful α-hydroxy ester derivatives in good ee (up to 95% ee). Furthermore, the substrate scope could be successfully extended to a range of phenols and alcohols with high yield (up to 92%) and excellent enantioselectivity (up to 97%) under mild reaction conditions. Additionally, a density functional theory (DFT) study was performed to elucidate the reaction mechanism. [ABSTRACT FROM AUTHOR]

A highly efficient and enantioselective hydrogenation of diversely substituted C=N-containing heterocyclic compounds such as 3-aryl-1,4-benzoxazines and 2-arylquinolines was experimentally explored by using 1,1′-spirobiindane-7,7′-diol-derived chiral phosphoric acids as the catalyst. This method provides straightforward access to the corresponding tetrahydroquinolines and dihydro-2 H-1,4-benzothiazines in high yields (85-99 %) with excellent enantioselectivities (91-99 %). The attractive features of this procedure, which include mild reaction conditions, operational simplicity, relatively low catalyst loading (1 mol-%), and high levels of enantioselectivities, make it a useful approach for the practical synthesis of optically active nitrogen-containing aromatic heterocycles. [ABSTRACT FROM AUTHOR]