Rhodium-Catalyzed Multicomponent-Coupling Reactions Involving a Carborhodation−Cross-Coupling Sequence
摘要:
A rhodium-catalyzed multicomponent-coupling reaction has been developed that involves a cross-coupling with organohalides as part of the reaction sequence. Through several experiments toward mechanistic investigations, it has also been demonstrated that the reaction most likely proceeds via a carborhodation-oxidative addition-reductive elimination pathway, which clearly contrasts to the corresponding palladium-catalyzed processes.
the stereoselectivesynthesis of various (E)-, (Z)-, and disubstituted 3-alkylideneoxindoles via radical cyclization reactions were investigated using tandem indium-mediated carbometallation and palladium-catalyzed cross-couplingreactions. The proper combination of substrates and reaction conditions is important for good yields. The key step is the first stereoselective carboindation reaction using
Synthesis, Structure and Emission Properties of Spirocyclic Benzofuranones and Dihydroindolones: A Domino Insertion–Coupling–Isomerization– Diels–Alder Approach to Rigid Fluorophores
作者:Daniel M. D'Souza、Alexander Kiel、Dirk-Peter Herten、Frank Rominger、Thomas J. J. Müller
DOI:10.1002/chem.200700759
日期:2008.1.7
far thermodynamically and kinetically favored over a possible Claisenrearrangement. Compounds of this new class of spirocyclic compounds possess large Stokes shifts and fluoresce intensively with blue over green to orange colors. As a consequence of the spirocyclic rigidity fluorescence lifetimes and quantum yields are rather high in some cases.
Copper‐Catalyzed Trifunctionalization of Alkynes: Rapid Formation of Oxindoles Bearing Geminal Diboronates
作者:Tao He、Bin Li、Li‐Chuan Liu、Jing Wang、Wen‐Peng Ma、Guang‐Yu Li、Qing‐Wei Zhang、Wei He
DOI:10.1002/chem.201804480
日期:——
A copper‐catalyzed trifunctionalization of alkynes that provides rapid access to oxindoles bearing a geminal diboronate side chain, highlighted by the simultaneous formation of one C−C bond and two C−B bonds, is reported. This new reaction features simple reaction conditions (ligand‐free catalysis), a general substrate scope, and excellent chemoselectivity. Mechanistic study revealed a reaction sequence
First Construction of Benzotellurazepine Ring System, 4-Methoxy-1,5-benzotellurazepines
作者:Haruki Sashida
DOI:10.3987/com-98-8111
日期:——
o-Iodopropiolanilides (3) reacted with sodium hydrogen telluride to give 1,5-benzotellurazepinones (5) via intramolecular cyclization of the presumable phenyltellurole intermediates (4). The lactams (5) were converted into the title lactim compounds, 4-methoxy-1,5-benzotellurazepines (7) by treatment with trimethyloxonium tetrafluoroborate.
Studies on Tellurium-Containing Heterocycles. Part 22. Tellurazepine Ring System: Preparation of 1,5-Benzotellurazepin-4-ones and Their Conversion into Fully Unsaturated 1,5-Benzotellurazepines
作者:Haruki Sashida、Hirohito Satoh
DOI:10.1248/cpb.52.413
日期:——
The treatment of o-iodopropiolanilides (12), which were easily prepared from o-iodophenylisocyanate (11) and ethynylmagnesium bromide, with sodium hydrogen telluride resulted in the intramolecular ring closure of the presumed phenyltellurol intermediates (13) to a triple bond to give the 1,5-benzotellurazepin-4-ones (14) as the sole characterized products. The obtained amides (14) were easily converted