Iridium- and rhodium-catalyzed C–H activation and formyl arylation of benzaldehydes under chelation-assistance
作者:Xifa Yang、He Wang、Xukai Zhou、Xingwei Li
DOI:10.1039/c6ob00825a
日期:——
Mild and efficient synthesis of benzophenones via Ir(iii)- and Rh(iii)-catalyzed, directing group-assisted formyl C–H arylation of benzaldehydes has been achieved using diaryliodonium salts, in which Rh(iii) and Ir(iii) catalysts exhibited a complementary substrate scope.
Ruthenium‐Catalyzed Direct Asymmetric Reductive Amination of Diaryl and Sterically Hindered Ketones with Ammonium Salts and H
<sub>2</sub>
作者:Le' an Hu、Yao Zhang、Qing‐Wen Zhang、Qin Yin、Xumu Zhang
DOI:10.1002/anie.201915459
日期:2020.3.23
A Ru-catalyzed directasymmetric reductive amination of ortho-OH-substituted diaryl and sterically hindered ketones with ammonium salts is reported. This method represents a straightforward route toward the synthesis of synthetically useful chiral primary diarylmethylamines and sterically hindered benzylamines (up to 97 % yield, 93->99 % ee). Elaborations of the chiral amine products into bioactive
phosphoranyl radical chemistry allows for precise cleavage of a stronger C-O bond and formation of a weaker C-Cbond by 1,5-aryl migration under mild reaction conditions. This new protocol is independent of substrate redox-potential, electronic, and substituent effects. It affords a general and promising access to 60 examples of synthetically versatile o-amino and o-hydroxy diaryl ketones under redox-neutral
C−H Oxygenation Reactions Enabled by Dual Catalysis with Electrogenerated Hypervalent Iodine Species and Ruthenium Complexes
作者:Leonardo Massignan、Xuefeng Tan、Tjark H. Meyer、Rositha Kuniyil、Antonis M. Messinis、Lutz Ackermann
DOI:10.1002/anie.201914226
日期:2020.2.17
The catalytic generation of hypervalent iodine(III) reagents by anodic electrooxidation was orchestrated towards an unprecedented electrocatalytic C−H oxygenation of weakly coordinating aromatic amides and ketones. Thus, catalytic quantities of iodoarenes in concert with catalytic amounts of ruthenium(II) complexes set the stage for versatile C−H activations with ample scope and high functional group
Synthesis of<i>ortho</i>-Hydroxybenzophenones Catalyzed by Magnetically Retrievable Fe<sub>3</sub>O<sub>4</sub>Nanoparticles under Ligand-Free Conditions
作者:Thekkathu Ramani、Paspulati Umadevi、K. Leon Prasanth、Bojja Sreedhar
DOI:10.1002/ejoc.201300909
日期:2013.9
ortho-Benzoylation of phenols with aryl aldehydes to afford the substituted 2-hydroxybenzophenones can be catalyzed efficiently by Fe3O4 nanoparticles underligand-freeconditions. This method is useful for the preparation of xanthones in good yields. The catalyst can be magnetically removed and recycled easily over four cycles without a significant decrease in activity.