Palladium(II)-Catalyzed ortho-Olefination of Arenes Applying Sulfoxides as Remote Directing Groups
摘要:
A novel palladium-catalyzed ortho-C(sp(2))-H olefination protocol has been developed by the use of sulfoxide as the directing group. Importantly, relatively remote coordination can be accessed to achieve the ortho olefination of benzyl, 2-arylethyl, and 3-arylpropenyl sulfoxide substrates, and the olefinated sulfoxide can be easily transformed to other functionalities.
A KOH-promoted unusual deoxidative coupling reaction of β-sulfinyl esters with benzylic trimethylammonium salts to produce thioethers is discovered for the first time. If quaternary ammonium salts synthesized from enantiomerically enriched amines are adopted, highlyenantiomerically enriched benzyl thioethers (>95–99% ee) with configurations opposite to those of the enantiomerically enriched amines
Thioethers as Directing Group for the Palladium-Catalyzed Direct Arylation of Arenes
作者:Jinzhong Yao、Ming Yu、Yuhong Zhang
DOI:10.1002/adsc.201200447
日期:2012.11.26
Thioethers have proven to be efficient directinggroups for the arylation of arenes under palladium catalysis. The thioethergroup can be readily removed or converted to other functional groups. Kinetic isotopic effect studies reveal that the CH cleavage of arenes might be the turnover-limiting step.
A novel palladium-catalyzed ortho-C(sp(2))-H olefination protocol has been developed by the use of sulfoxide as the directing group. Importantly, relatively remote coordination can be accessed to achieve the ortho olefination of benzyl, 2-arylethyl, and 3-arylpropenyl sulfoxide substrates, and the olefinated sulfoxide can be easily transformed to other functionalities.