Cascade Palladium Catalysis: A Predictable and Selectable Regiocontrolled Synthesis of<i>N</i>-Arylbenzimidazoles
作者:Nathan T. Jui、Stephen L. Buchwald
DOI:10.1002/anie.201306007
日期:2013.10.25
choice: The palladium‐catalyzed cascade reaction of 2‐chloroaryl sulfonates with arylamine and amide nucleophiles provides direct access to N‐arylbenzimidazoles. This strategy selectively produces the heterocycles based on chemoselective oxidative addition. 2‐Chloroaryl triflates (Tf) produce one regioisomer and the corresponding 2‐chloroaryl mesylates (Ms) deliver the other in a selectable manner.
zinc bromides and regioconvergent Negishi coupling with aryl or alkenyl triflates. The use of a suitable phosphine ligand favoring Pd migration enabled the selective formation of the linear cross‐coupling product. Subsequently, mixtures of secondary alkyl bromides were prepared from linear alkanes by standard bromination, and regioconvergent cross‐coupling then provided access to the corresponding linear
Inverting Conventional Chemoselectivity in the Sonogashira Coupling Reaction of Polyhalogenated Aryl Triflates with TMS-Arylalkynes
作者:Miao Wang、Chau Ming So
DOI:10.1021/acs.orglett.1c04138
日期:2022.1.21
Sonogashira couplingreaction with excellent chemoselectivity, affording an inversion of the conventional chemoselectivity order of C–Br > C–Cl > C–OTf. This study also provided an efficient approach to the synthesis of polycyclic aromatic hydrocarbons (PAHs) and the natural product analogue trimethyl-selaginellin L by merging of chemoselective Sonogashira and Suzuki–Miyaura couplingreactions.
Highly stereoselective and catalytic desulfitative C O and C I dienylation with sulfolenes: The importance of basic additives
作者:Hang T. Dang、Viet D. Nguyen、Hoang H. Pham、Hadi D. Arman、Oleg V. Larionov
DOI:10.1016/j.tet.2019.04.012
日期:2019.6
organic synthesis and materials science. We describe herein a palladium-catalyzeddienylation of aryl, heteroaryl, and vinyl triflates, nonaflates and iodides that were previously identified as recalcitrant substrates for the sulfolene-mediated catalytic dienylation. The method has now been successfully expanded to C-O and C-I dienylation, demonstrating broad scope with respect to sulfonates, iodides
Cationic Alkynyl Heck Reaction toward Substituted Allenes Using BobCat: A New Hybrid Pd(0)-Catalyst Incorporating a Water-Soluble dba Ligand
作者:Robynne K. Neff、Doug E. Frantz
DOI:10.1021/jacs.8b11759
日期:2018.12.19
cationic alkynyl Heck reaction between aryl triflates and alkynes to give substituted allenes is described. Key to the success of this method was the discovery and development of a new hybrid Pd(0)-catalyst, BobCat, that incorporates a water-soluble dba-ligand and biaryl phosphine ligand to provide substituted allenes in good yields under mild reaction conditions.