Cyanomethylation of Substituted Fluorenes and Oxindoles with Alkyl Nitriles
作者:Gang Hong、Pradip D. Nahide、Marisa C. Kozlowski
DOI:10.1021/acs.orglett.0c00160
日期:2020.2.21
cyanomethylenation from alkyl nitriles of sp3 C–H bonds to afford quaternary carbon centers is described. This oxidative protocol is operationally simple and features good functional group compatibility. This method provides a novel approach to highly functionalized fluorene and oxindole derivatives, which are commonly used in material and pharmaceutical areas. Control experiments provide evidence of a radical
Palladium-Catalyzed Chemoselective Activation of sp<sup>3</sup> vs sp<sup>2</sup> C–H Bonds: Oxidative Coupling To Form Quaternary Centers
作者:Gang Hong、Pradip D. Nahide、Uday Kumar Neelam、Peter Amadeo、Arjun Vijeta、John M. Curto、Charles E. Hendrick、Kelsey F. VanGelder、Marisa C. Kozlowski
DOI:10.1021/acscatal.9b00091
日期:2019.4.5
activation of alkyl C–H bonds vs arene C–H bonds with Pd(OAc)2 has been found to be generalizable to a number of nucleophilic substrates, allowing the formation of a range of hindered quaternary centers. The substrates share a common mechanistic path wherein Pd(II) initiates an oxidative dimerization. The resultant dimer modifies the palladium catalyst to favor activation of alkyl C–H bonds, in contrast to
Copper-Catalyzed Asymmetric Propargylic Alkylation with Oxindoles: Diastereo- and Enantioselective Construction of Vicinal Tertiary and All-Carbon Quaternary Stereocenters
作者:Jin-Tao Xia、Xiang-Ping Hu
DOI:10.1021/acs.orglett.9b04621
日期:2020.2.7
stereoselective construction of vicinal tertiary and all-carbon quaternary stereocenters in a 3,3-disubstituted oxindole skeleton has been realized. The reaction proceeded smoothly under the catalysis of Cu(MeCN)4PF6 combined with a chiral tridentateferrocenyl P,N,N ligand, leading to a broad range of optically active 3,3-disubstituted oxindoles in high yields and with excellent diastereo- and enantioselectivities
<scp>Pd‐Catalyzed</scp>
2,
<scp>3‐Allenylation</scp>
of Oxindoles with 2,
<scp>3‐Allenylic</scp>
Carbonates
作者:Jie Lin、Minqiang Jia、Shengming Ma
DOI:10.1002/cjoc.202100402
日期:2021.11
Allenes and oxindoles are two classes of very important compounds for medicinal chemistry and organic chemistry. Thus, it is of high interest to combine an allene and an oxindole into one molecule. Herein, the first example of palladium-catalyzed exclusive 2,3-allenylation reaction of oxindoles with 2,3-allenylic carbonates has been successfully developed. A rationale for the selectivity of 2,3-allenylation
A Palladium-Catalyzed α-Arylation of Oxindoles with Aryl Tosylates
作者:Jindian Duan、Fuk Yee Kwong
DOI:10.1021/acs.joc.7b00855
日期:2017.6.16
A palladium-catalyzed monoselective C3 arylation of 2-oxindoles with aryl tosylates is described. With the Pd/CM-phos catalyst system, the corresponding 3-arylated oxindoles can be obtained in good to excellent yields (≤97%). The reaction conditions are mild (using 0.5 mol % Pd in general and KF as a base), and functional groups such as methyl ester, NH amido, and enolizable keto moieties are found