Rh<sup>III</sup>-Catalyzed Dehydrogenative Coupling of Quinoline<i>N</i>-Oxides with Alkenes:<i>N</i>-Oxide as Traceless Directing Group for Remote C-H Activation
A RhIII-catalyzeddehydrogenativecoupling reaction of quinoline N-oxides with alkenes has been developed that provides C-8 olefinated quinoline derivatives by employing a remoteC–Hactivation strategy. Main features of this catalytic method include the use of N-oxide as a tracelessdirectinggroup, the high selectivity of the reaction for the C-8 position, and the broad scope of possible substrates
A cobalt(III)-catalyzed C-8 selective C–H amidation of quinoline N-oxide using dioxazolone as an amidating reagentundermildconditions is disclosed. The reaction proceeds efficiently with excellent functional group compatibility. The utility of the current method is demonstrated by gram scale synthesis of C-8 amide quinoline N-oxide and by converting this amidated product into functionalized quinolines
amination/annulation strategy was developed for the synthesis of benzophenanthroline derivativesusing quinoline N‐oxides and anthranils. The method was further extended to the synthesis of nitrogen‐containing extended π‐conjugated benzophenanthrolinone derivatives. Late‐stage functionalizations of cinchonidine and cinchophen derivatives and synthesis of a bioactive quinolino‐indole were achieved.
rhodium(III)‐catalyzed regioselective distal C(sp2)‐H bond alkylation of quinoline N‐oxides using olefins as alkyl source and N‐oxide as the traceless directing group. The reaction exhibits broad substrate scope with excellent selectivity for C‐8 position and good yields of alkylated products. The usefulness of the developed catalytic protocol is established by synthesis of EP4 agonist. In mechanistic study, C‐8 olefinated
Rhodium(III)-Catalyzed CC and CO Coupling of Quinoline<i>N</i>-Oxides with Alkynes: Combination of CH Activation with O-Atom Transfer
作者:Xueyun Zhang、Zisong Qi、Xingwei Li
DOI:10.1002/anie.201406747
日期:2014.9.26
[Cp*RhIII]‐catalyzed CH activation of arenes assisted by an oxidizing NO or NN directing group has allowed the construction of a number of hetercycles. In contrast, a polar NO bond is well‐known to undergo O‐atom transfer (OAT) to alkynes. Despite the liability of NO bonds in both CH activation and OAT, these two important areas evolved separately. In this report, [Cp*RhIII] catalysts integrate