A palladium-catalyzed enantioselective hydroesterification of alkenylphenols with phenyl formate. A facile approach to optically active dihydrocoumarins
作者:Jingfu Li、Wenju Chang、Wenlong Ren、Wei Liu、Haining Wang、Yian Shi
DOI:10.1039/c5ob01431j
日期:——
An effective palladium-catalyzed enantioselective hydroesterification of alkenylphenols with phenyl formate as a CO source is described.
Rhodium(<scp>iii</scp>)-catalyzed [5+1] annulation of 2-alkenylphenols with maleimides: access to highly functionalized spirocyclic skeletons
作者:Anil Kumar、Kandikere Ramaiah Prabhu
DOI:10.1039/d1cc01758f
日期:——
A new edition of [5+1] annulation reaction of maleimides with 2-alkenylphenols has been discovered under a Rh(III)-catalytic system. The process leads to an efficient synthesis of valued spirocyclic scaffolds bearing an oxygen-containing spiro carbon in a single step and shows a broad substrate scope with good functional group tolerance. The synthetic utility has been exemplified by synthesizing highly
在Rh( III )-催化体系下发现了马来酰亚胺与2-烯基苯酚的[5+1]环化反应的新版本。该过程导致在单个步骤中有效合成带有含氧螺碳的有价值的螺环支架,并显示出具有良好官能团耐受性的广泛底物范围。合成效用已通过合成高度官能化的 2,2-二取代-2 H-色烯骨架和低催化剂负载的克级合成来举例说明。
Cobalt(III)-Catalyzed [5 + 1] Annulation for 2<i>H</i>-Chromenes Synthesis via Vinylic C–H Activation and Intramolecular Nucleophilic Addition
new cobalt-catalyzed phenolic OH-assisted C–H functionalization of 2-vinylphenols with allenes to give various 2H-chromenes is described. It is the first time that allenes are used as the coupling partners in the cobalt-catalyzed C–H activation reactions. In most cases, cobalt-catalyzed oxidative annulation of arenes with alkenes or alkynes via C–H activation gave [4 + 2] or [3 + 2] cyclization products
propargyl carbonates have been developed by using two O-containing functional groups as the traceless assisting groups (AGs). The experimental investigations together with the density functional theory (DFT) calculations revealed that this transformation involves the free OH-directed cleavage of one terminal C–H bond of the alkenyl moiety and regioselective alkyne insertion, followed by OBoc-promoted intramolecular
Merging Chiral Brønsted Acid/Base Catalysis: An Enantioselective [4 + 2] Cycloaddition of <i>o</i>-Hydroxystyrenes with Azlactones
作者:Yu-Chen Zhang、Qiu-Ning Zhu、Xue Yang、Lu-Jia Zhou、Feng Shi
DOI:10.1021/acs.joc.6b00078
日期:2016.2.19
An enantioselective [4 + 2] cycloaddition of o-hydroxylstyrenes with azlactones has been established by merging chiralBrønstedacid (chiral phosphoric acid) and base (chiral guanidine) catalysis, which constructed a biologically important dihydrocoumarin scaffold in an efficient and enantioselective style (up to 99% yield, 96:4 er). This approach has not only realized the successful application of