Enantioselective Intermolecular Heck and Reductive Heck Reactions of Aryl Triflates, Mesylates, and Tosylates Catalyzed by Nickel
作者:Xiaolei Huang、Shenghan Teng、Yonggui Robin Chi、Wenqiang Xu、Maoping Pu、Yun‐Dong Wu、Jianrong Steve Zhou
DOI:10.1002/anie.202011036
日期:2021.2.8
Nickel‐catalyzed intermolecular Heckreaction of cycloalkenes proceeds well with aryl triflates, mesylates and tosylates in excellent enantiomeric ratios. The asymmetric reductive Heckreaction also works with a 2‐cyclopentenone ketal, which is equivalent to conjugate arylation of the enone itself.
Herein, we first present a nickel-catalyzed arylation and alkenylation of tert-cyclobutanols with aryl/alkenyl triflates via a C–Cbondcleavage. An array of γ-substituted ketones was obtained in moderate-to-good yields, thus featuring earth-abundant nickel catalysis, broad substrate scope, and simple reaction conditions. Preliminary mechanistic experiments indicated that β-carbon elimination pathways
NiCl2-catalyzed P–C coupling reaction of arylhalides and various > P(O)H-compounds under MW conditions without directly added P-ligands. The reactivity of a few aryl derivatives in the Pd(OAc)2-catalyzed Hirao reaction was also studied. An induction period was observed in the reaction of bromobenzene and diphenylphosphine oxide. Finally, the less known copper(I)-promoted P–C coupling reactions were investigated
Photoinduced phosphonation of aryl triflates with trialkyl phosphites via a tandem single-electron-transfer, C–O bond cleavage and Arbuzov rearrangement process in the absence of transition-metal and external photosensitizer is reported herein. The protocol features good functional group compatibility and mild reaction conditions, providing various aryl phosphates in good to high yields. Furthermore
Nickel-catalyzed Heck reaction of cycloalkenes using aryl sulfonates and pivalates
作者:Jianrong Steve Zhou、Xiaolei Huang、Shenghan Teng、Yonggui Robin Chi
DOI:10.1039/d1cc00634g
日期:——
Nickel-catalyzed Heck reaction of cycloalkenes delivers unusual conjugated arylated isomers. Nickel(0) catalysts ligated by chelating dialkylphosphines effectively activate not only aryl triflates as electrophiles, but also less reactive aryl mesylates, tosylates and pivalates. The omission of bases allows nickel hydride species to exist long enough to perform in situ olefin isomerization of initial