Synthesis of Dibenzopyranones through Palladium-Catalyzed Directed C-H Activation/Carbonylation of 2-Arylphenols
作者:Shuang Luo、Fei-Xian Luo、Xi-Sha Zhang、Zhang-Jie Shi
DOI:10.1002/anie.201304295
日期:2013.9.27
Dibenzopyranones were synthesized by a palladium‐catalyzed phenol‐directed C–H activation/carbonylation of 2‐phenylphenol derivatives in the presence of CO. Pd(OAc)2 was used as a catalyst and Cu(OAc)2 as a catalytic oxidant in the presence of air.
Palladium-Catalyzed Sequential C(<i>sp</i>
<sup>2</sup>
)-H Alkynylation/Annulation of 2-Phenylphenols with Haloalkynes Using Phenolic Hydroxyl as the Traceless Directing Group
An efficient, palladium(II)‐catalyzed, C(sp2)‐H alkynylation/annulation of 2‐phenylphenols with haloalkynes for the synthesis of substituted 6‐methylene‐6H‐dibenzo[b,d]pyrans is reported. This protocol features a traceless directing group strategy, unique regioselectivity and mild reaction conditions. Significantly, preliminary mechanistic studies suggest that the sequential C(sp2)‐H alkynylation and
Annulations of unsaturated systems through C–H activation represent a powerful tool for producing multicyclic scaffolds. Having coordinating centers in both annulation partners (a dual coordination strategy) would afford remarkable selectivities in the outcomes. Along this concept, we report herein a Pd-catalyzed regioselective rollover cascade dual C–H annulation of o-arylphenols with alkynols for
Oxidative Cyclization of 2-Arylphenols to Dibenzofurans under Pd(II)/Peroxybenzoate Catalysis
作者:Ye Wei、Naohiko Yoshikai
DOI:10.1021/ol202229w
日期:2011.10.21
2-Arylphenols undergo intramolecular C-H bond activation/C-O bond formation to afford dibenzofuran derivatives under palladium catalysis In the presence of tert-butyl peroxybenzoate as an oxidant. Kinetic isotope effect experiments indicated that C-H bond cleavage Is the rate-limiting step of the reaction.
Ruthenium-Catalyzed Carbonylative C–H Cyclization of 2-Arylphenols: A Novel Synthetic Route to 6<i>H</i>-Dibenzo[<i>b,d</i>]pyran-6-ones
作者:Kiyofumi Inamoto、Jun Kadokawa、Yoshinori Kondo
DOI:10.1021/ol401734m
日期:2013.8.2
Catalytic carbonylative C-H cyclization of 2-arylphenols can be achieved in the presence of a ruthenium-based catalytic system. The process proceeds efficiently under balloon pressure of CO and produces variously substituted 6H-dibenzo[b,d]pyran-6-one compounds, typically in good to high yields. Functional groups such as the alkoxycarbonyl and acetyl groups as well as halogen atoms (F, Cl, and Br) are well tolerated during the reaction.