η ⁶‐(1‐Oxobenzocyclobutene)tricarbonylchromium(0)

Preparation, Reduction, and Ring-Opening/Cycloaddition Chemistry of the 1-Hydroxybenzocyclobutene Complex

verfasst von

Michael Brands, Hans G. Wey, Rainer Krömer, Carl Krüger, Holger Butenschön

Abstract

The syntheses of the tricarbonylchromium complexes 2 and 3 of 1‐oxobenzocyclobutene and 1‐hydroxybenzocyclobutene are described. Alcoholate 6 of 3 undergoes a ring opening to the corresponding ortho‐quinodimethane intermediate between −30 and −20°C, which is trapped by dienophiles with high diastereoselectivity. While with most dienophiles products with a 1,2‐cis configuration (7, 8, 10) are formed, vinyl sulfones react in an exo‐selective cycloaddition with formation of 1,2‐trans‐configurated cycloadducts (12, 13). The configuration of the cycloadduct with phenyl vinyl sulfone is confirmed by an X‐ray crystal structure analysis. As one of the important aspects of the chemistry of benzocyclobutene complexes is the chirality of compounds like 2 and 3, the enantiomeric resolution has been achieved via the semioxamazones of ketone 2.

Externe Organisation(en)

Max-Planck-Institut für Kohlenforschung

Typ

Artikel

Journal

Liebigs Annalen

Band

1995

Seiten

253-265

Anzahl der Seiten

13

ISSN

0947-3440

Publikationsdatum

27.01.1995

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Allgemeine Chemie

Elektronische Version(en)

https://doi.org/10.1002/jlac.199519950235 (Zugang: Unbekannt)