Rhodium(III)-Catalyzed<i>ortho</i>Alkenylation of<i>N</i>-Phenoxyacetamides with<i>N</i>-Tosylhydrazones or Diazoesters through CH Activation
作者:Fangdong Hu、Ying Xia、Fei Ye、Zhenxing Liu、Chen Ma、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201309650
日期:2014.1.27
A coupling reaction of N‐phenoxyacetamides with N‐tosylhydrazones or diazoestersthrough RhIII‐catalyzed CHactivation is reported. In this reaction, ortho‐alkenyl phenols were obtained in good yields and with excellent regio‐ and stereoselectivity. Rh–carbene migratory insertion is proposed as the key step in the reaction mechanism.
A Palladium-Catalyzed Regioselective Hydroesterification of Alkenylphenols to Lactones with Phenyl Formate as CO Source
作者:Haining Wang、Ben Dong、Yang Wang、Jingfu Li、Yian Shi
DOI:10.1021/ol403171p
日期:2014.1.3
An effective Pd(OAc)2-PPh3 catalyzed hydroesterification of alkenylphenols with phenyl formate as CO surrogate is described. A variety of lactones are obtained in generally high yields with high regioselectivities. In one case, 76% ee is obtained with a chiral ligand.
Palladium-catalyzed synthesis of benzofurans via C–H activation/oxidation tandem reaction and its application to the synthesis of decursivine and serotobenine
A new palladium-catalyzed method for the synthesis of benzofurans by reaction of 2-hydroxystyrenes and iodobenzenes via a CâH activation/oxidation tandem reaction has been unprecedentedly discovered. By using this strategy, the overall synthetic efficiency of the synthesis of decursivine and its analogues was indeed improved. Preliminary mechanistic studies shed light into the possible mechanisms.
OH-Directed Alkynylation of 2-Vinylphenols with Ethynyl Benziodoxolones: A Fast Access to Terminal 1,3-Enynes
作者:Peter Finkbeiner、Ulrich Kloeckner、Boris J. Nachtsheim
DOI:10.1002/anie.201412148
日期:2015.4.13
The first direct alkynylation of 2‐vinylphenols was developed. The rationally optimized hypervalent iodine reagent TIPS‐EBX* in combination with [(Cp*RhCl2)2] as a CH‐activating transition metal catalyst enables the construction of a variety of highly substituted 1,3‐enynes in high yields of up to 98 %. This novel CH activation method shows excellent chemoselectivity and exclusive (Z)‐stereoselectivity