TY - JOUR
T1 - Synthesis, structure and emission properties of spirocyclic benzofuranones and dihydroindolones: A domino insertion-coupling-isomerization-Diels-Alder approach to rigid fluorophores
AU - D'Souza, Daniel M.
AU - Kiel, Alexander
AU - Herten, Dirk-Peter
AU - Rominger, Frank
AU - Mueller, Thomas J. J.
PY - 2008
Y1 - 2008
N2 - 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.
AB - 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.
UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000252457600012&KeyUID=WOS:000252457600012
U2 - 10.1002/chem.200700759
DO - 10.1002/chem.200700759
M3 - Article
SN - 0947-6539
JO - Chemistry: A European Journal
JF - Chemistry: A European Journal
ER -