Premium
Synthesis, Structure and Emission Properties of Spirocyclic Benzofuranones and Dihydroindolones: A Domino Insertion–Coupling–Isomerization– Diels–Alder Approach to Rigid Fluorophores
Author(s) -
D'Souza Daniel M.,
Kiel Alexander,
Herten DirkPeter,
Rominger Frank,
Müller Thomas J. J.
Publication year - 2008
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200700759
Subject(s) - pericyclic reaction , chemistry , isomerization , claisen rearrangement , intramolecular force , sonogashira coupling , substituent , steric effects , domino , photochemistry , fluorescence , aryl , cyclooctatetraene , stereochemistry , computational chemistry , organic chemistry , molecule , physics , palladium , catalysis , alkyl , quantum mechanics
An alkynoyl ortho ‐iodo phenolester or alkynoyl ortho ‐iodo anilides and propargyl allyl ethers react under Sonogashira coupling conditions in the sense of an insertion–coupling–isomerization–Diels–Alder hetero domino reaction to furnish (tetrahydroisobenzofuran)‐spirobenzofuranones and ‐spirodihydroindolones in good yields. Many representatives can be crystallized and single crystal structure analyses display steric and electronic substituent effects on the torsional angles of the terminal (hetero)aryl groups and the central cis , trans ‐butadiene fragment. DFT computations reveal that in the final pericyclic step the Diels–Alder termination is by far thermodynamically and kinetically favored over a possible Claisen rearrangement. 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.