Carboxy-directed asymmetric hydrogenation of α-alkyl-α-aryl terminal olefins: highly enantioselective and chemoselective access to a chiral benzylmethyl center
A carboxy-directedasymmetrichydrogenation of α-alkyl-α-aryl terminal olefins was developed by using a chiral spiro iridium catalyst, providing a highly efficient approach to the compounds with a chiral benzylmethyl center. The carboxy-directedhydrogenation prohibited the isomerization of the terminal olefins, and realized the chemoselective hydrogenation of various dienes. The concise enantioselective
Enantioselective Palladium(II)-Catalyzed Intramolecular Aminoarylation of Alkenes by Dual N−H and Aryl C−H Bond Cleavage
作者:Wen Zhang、Pinhong Chen、Guosheng Liu
DOI:10.1002/anie.201700889
日期:2017.5.2
An asymmetric palladium‐catalyzed intramolecular oxidative aminoarylation of alkenes has been developed with quinoline–oxazoline chiral ligands and Ag2CO3 as the oxidant. Various indolines containing a quaternary stereogenic center were synthesized in high yield with excellent enantioselectivity. Preliminary mechanistic studies suggest that the addition of a catalytic amount of phenylglyoxylic acid
用喹啉-恶唑啉手性配体和Ag 2 CO 3作为氧化剂,开发了不对称钯催化的烯烃分子内氧化氨基芳基化反应。含有四元立体异构中心的各种二氢吲哚以高产率合成,具有出色的对映选择性。初步的机理研究表明,加入催化量的苯乙醛酸可显着加快反应速度,并略微提高对映选择性。
Highly Enantioselective Asymmetric Hydrogenation of Carboxy-Directed α,α-Disubstituted Terminal Olefins via the Ion Pair Noncovalent Interaction
The t-Bu-Wudaphos was successfully applied into Rh-catalyzed asymmetric hydrogenation of α,α-disubstituted terminal olefins bearing a carboxy-directed group with excellent reactivities and enantioselectivities via the ion pair noncovalent interaction (up to >99% conversion, 98% yield, 98% ee) under mild reactionconditionswithout base. In addition, control experiments were conducted, and the results
Aryl iodine-catalysed divergent synthesis of isobenzofuranones and isocoumarins <i>via</i> oxidative 1,2-aryl migration/elimination
作者:Jiaxin He、Jingran Zhang、Xuemin Li、Haofeng Shi、Yunfei Du
DOI:10.1039/d2cc03101a
日期:——
The divergent synthesis of isobenzofuranones and isocoumarins was realized from the reaction of 2-alkenyl benzoic acids and mCPBA in the presence of catalytic aryl iodine and (±)-10-camphorsulfonic acid (CSA). The organocatalytic oxidative reaction is assumed to undergo a cascade process involving lactonization, 1,2-aryl migration and elimination enabled by a modified Koser reagent generated in situ
Enantioselective Synthesis of Isoindolinone by Palladium-Catalyzed Aminoalkynylation of O-Phenyl Hydroxamic Ethers with Alkynes
作者:Lei Wang、Yinqiang Wang、Shuaijie Wu、Chao-Guo Yan、Chaoshen Zhang、Junliang Zhang、Ying Han
DOI:10.1021/jacs.3c12996
日期:2024.2.21
A highly efficient palladium-catalyzed asymmetric tandem aza-Heck/Sonogashira coupling reaction of O-phenyl hydroxamic ethers with terminal alkynes is described. This protocol enables versatile access to challenging chiral isoindolinone derivatives bearing a quaternarystereogeniccenter. The palladium-catalyzed aminoalkynylation reaction shows broad functional group tolerance and allows the straightforward