heteroarenyne (heteroarene–alkyne) cycloisomerization involving the dearomative transformation of endocyclic aromatic C=C bonds remains unknown. Herein, we communicate a PdH‐catalyzed enantioselective heteroarenyne cycloisomerization reaction of alkyne‐tethered indole substrates (formal 1,5‐ and 1,6‐enynes). Based on this strategy, a variety of structurally diverse chiral spiro and fused indoline derivatives
Palladium(0)-Catalyzed Intermolecular Asymmetric Allylic Dearomatization of Polycyclic Indoles
作者:Run-Duo Gao、Lu Ding、Chao Zheng、Li-Xin Dai、Shu-Li You
DOI:10.1021/acs.orglett.7b03887
日期:2018.2.2
An intermolecular Pd-catalyzed allylic dearomatization reaction of polycyclic indoles with substituted allylic carbonates was realized in the presence of a newly synthesized chiral phosphoramidite ligand. Various polycyclic indoline and indolenine derivatives were successfully synthesized in excellent yields (up to 99%) with excellent enantioselectivity (up to 98% ee). The obtained products could undergo
A copper-catalyzed tunable oxygenative rearrangement reaction of tetrahydrocarbazoles by using H2O and O2 as oxygen source has been developed. Accordingly, highly important yet synthetically difficult cyclopentyl-bearing spiroindolin-2-one and spiroindolin-3-one products were obtained with excellent chemoselectivity and regioselectivity. Inspired from the unique pathway of 1, 2-migration rearrangement
Tetrahydrocarbazoles and perhydrocyclohepta[b]indoles undergo a catalytic cascade singlet oxygenation in alkaline medium, which leads to chiral tricyclic perhydropyrido‐ and perhydroazepino[1,2‐a]indoles in a single operation. These photooxygenation products are new synthetic equivalents of uncommon C,N‐diacyliminiumions and can be functionalized with the aid of phosphoric acid organocatalysis.
Reductive Cyclization of <i>o</i>-Nitroarylated-α,β-unsaturated Aldehydes and Ketones with TiCl<sub>3</sub>/HCl or Fe/HCl Leading to 1,2,3,9-Tetrahydro-4<i>H</i>-carbazol-4-ones and Related Heterocycles
作者:Yun Qiu、Michael Dlugosch、Xin Liu、Faiyaz Khan、Jas S. Ward、Ping Lan、Martin G. Banwell
DOI:10.1021/acs.joc.8b01940
日期:2018.10.5
Compounds such as 3, the product of a palladium[0]-catalyzed Ullmann cross-coupling of o-iodonitrobenzene and 2-iodocyclohex-2-en-1-one, undergo complementary modes of reductive cyclization depending upon the conditions employed. Thus, on treatment with hydrogen in the presence of palladium on carbon, the tetrahydrocarbazole 4 is formed, while reaction of the same substrate (3) with TiCl3 in acetone