A Palladium-Catalyzed Approach to Polycyclic Sulfur Heterocycles
摘要:
The synthesis of a variety of polycyclic thiophenes and benzothiophenes is accomplished via a palladium-catalyzed domino ortho-alkylation/direct arylation reaction. An examination of the intramolecular direct arylation of thiophenes suggests that an electrophilic metalation mechanism may be present. This method was further extended to include the synthesis of a (thieno)benzoxepine.
Palladium-Catalyzed Cascade CH Trifluoroethylation of Aryl Iodides and Heck Reaction: Efficient Synthesis of<i>ortho</i>-Trifluoroethylstyrenes
作者:Hao Zhang、Pinhong Chen、Guosheng Liu
DOI:10.1002/anie.201403793
日期:2014.9.15
A palladium‐catalyzed selective CH bond trifluoroethylation of aryl iodides has been explored. The reaction allows for the efficient synthesis of a variety of ortho‐trifluoroethyl‐substituted styrenes. Preliminary mechanisticstudies indicate that the reaction might involve a key PdIV intermediate, which is generated through the rate‐determining oxidative addition of CF3CH2I to a palladacycle; the
A palladium-catalyzed C-H functionalization reaction for the synthesis of highly substituted aromatic nitriles is reported. The modularity of the reaction is demonstrated by the broad range of aryl iodides which can be coupled with metalcyanides and alkylhalides or aryl bromides.
Synthesis of Annulated 2<i>H</i>-Indazoles and 1,2,3- and 1,2,4-Triazoles via a One-Pot Palladium-Catalyzed Alkylation/Direct Arylation Reaction
作者:Benoît Laleu、Mark Lautens
DOI:10.1021/jo8017236
日期:2008.11.21
A variety of six-membered-ring annulated 2H-indazoles and 1,2,3- and 1,2,4-triazoles were synthesized in good to excellent yields from the corresponding bromoethyl azoles and aryl iodides. The annulation process involves a one-pot norbornene-mediated palladium-catalyzed sequence whereby an alkyl-aryl bond and an aryl-heteroaryl bond are successively formed through two C-H bond activations. Subsequent
Synthesis of Polycyclic Heterocycles via a One-Pot Ortho Alkylation/Direct Heteroarylation Sequence
作者:Andrew Martins、Dino Alberico、Mark Lautens
DOI:10.1021/ol061859+
日期:2006.10.1
Polycyclic thiophenes and furans were synthesized using a one-pot ortho alkylation/direct heteroarylation reaction sequence. Under the optimized reaction conditions, aryl iodides were coupled with 3-(bromoalkyl) thiophenes or -furans, affording six-and seven-membered annulated ring products via formation of two C-C bonds from two aryl C-H bonds.