---
_id: '37984'
abstract:
- lang: eng
  text: <jats:p>The Wittig reaction is a fundamental transformation for the preparation
    of alkenes from carbonyl compounds and phosphonium ylides. The ylides are prepared
    prior to the olefination step from the respective phosphonium salts by deprotonation
    utilizing strong bases. A first free-base catalytic Wittig reaction for the preparation
    of highly functionalized alkenes was based on tributylphosphane as the catalyst.
    Subsequently we developed a system employing a phospholene oxide as a pre-catalyst
    and trimethoxysilane as reducing agent which operates under milder conditions.
    The title compounds, (<jats:italic>E</jats:italic>)-3-benzylidenepyrrolidine-2,5-dione,
    C<jats:sub>11</jats:sub>H<jats:sub>9</jats:sub>NO<jats:sub>2</jats:sub>, (I),
    the methylpyrrolidine derivative, C<jats:sub>12</jats:sub>H<jats:sub>11</jats:sub>NO<jats:sub>2</jats:sub>,
    (II), and the<jats:italic>tert-</jats:italic>butylpyrrolidine derivative, C<jats:sub>15</jats:sub>H<jats:sub>17</jats:sub>NO<jats:sub>2</jats:sub>,
    (III), have been synthesized by base-free catalytic Wittig reactions. In the crystal
    of (I), molecules are linked into centrosymmetric dimers<jats:italic>via</jats:italic>pairs
    of N—H...O hydrogen bonds. Furthermore, in the crystal structure of (III), there
    are two molecules in the asymmetric unit, whereas in (I) and (II), only one molecule
    is present.</jats:p>
author:
- first_name: Marie-Luis
  full_name: Schirmer, Marie-Luis
  last_name: Schirmer
- first_name: Anke
  full_name: Spannenberg, Anke
  last_name: Spannenberg
- first_name: Thomas
  full_name: Werner, Thomas
  id: '89271'
  last_name: Werner
  orcid: 0000-0001-9025-3244
citation:
  ama: 'Schirmer M-L, Spannenberg A, Werner T. Highly functionalized alkenes produced
    from base-free organocatalytic Wittig reactions: (<i>E</i>)-3-benzylidenepyrrolidine-2,5-dione,
    (<i>E</i>)-3-benzylidene-1-methylpyrrolidine-2,5-dione and (<i>E</i>)-3-benzylidene-1-<i>tert</i>-butylpyrrolidine-2,5-dione.
    <i>Acta Crystallographica Section C Structural Chemistry</i>. 2016;72(6):504-508.
    doi:<a href="https://doi.org/10.1107/s2053229616008159">10.1107/s2053229616008159</a>'
  apa: 'Schirmer, M.-L., Spannenberg, A., &#38; Werner, T. (2016). Highly functionalized
    alkenes produced from base-free organocatalytic Wittig reactions: (<i>E</i>)-3-benzylidenepyrrolidine-2,5-dione,
    (<i>E</i>)-3-benzylidene-1-methylpyrrolidine-2,5-dione and (<i>E</i>)-3-benzylidene-1-<i>tert</i>-butylpyrrolidine-2,5-dione.
    <i>Acta Crystallographica Section C Structural Chemistry</i>, <i>72</i>(6), 504–508.
    <a href="https://doi.org/10.1107/s2053229616008159">https://doi.org/10.1107/s2053229616008159</a>'
  bibtex: '@article{Schirmer_Spannenberg_Werner_2016, title={Highly functionalized
    alkenes produced from base-free organocatalytic Wittig reactions: (<i>E</i>)-3-benzylidenepyrrolidine-2,5-dione,
    (<i>E</i>)-3-benzylidene-1-methylpyrrolidine-2,5-dione and (<i>E</i>)-3-benzylidene-1-<i>tert</i>-butylpyrrolidine-2,5-dione},
    volume={72}, DOI={<a href="https://doi.org/10.1107/s2053229616008159">10.1107/s2053229616008159</a>},
    number={6}, journal={Acta Crystallographica Section C Structural Chemistry}, publisher={International
    Union of Crystallography (IUCr)}, author={Schirmer, Marie-Luis and Spannenberg,
    Anke and Werner, Thomas}, year={2016}, pages={504–508} }'
  chicago: 'Schirmer, Marie-Luis, Anke Spannenberg, and Thomas Werner. “Highly Functionalized
    Alkenes Produced from Base-Free Organocatalytic Wittig Reactions: (<i>E</i>)-3-Benzylidenepyrrolidine-2,5-Dione,
    (<i>E</i>)-3-Benzylidene-1-Methylpyrrolidine-2,5-Dione and (<i>E</i>)-3-Benzylidene-1-<i>Tert</i>-Butylpyrrolidine-2,5-Dione.”
    <i>Acta Crystallographica Section C Structural Chemistry</i> 72, no. 6 (2016):
    504–8. <a href="https://doi.org/10.1107/s2053229616008159">https://doi.org/10.1107/s2053229616008159</a>.'
  ieee: 'M.-L. Schirmer, A. Spannenberg, and T. Werner, “Highly functionalized alkenes
    produced from base-free organocatalytic Wittig reactions: (<i>E</i>)-3-benzylidenepyrrolidine-2,5-dione,
    (<i>E</i>)-3-benzylidene-1-methylpyrrolidine-2,5-dione and (<i>E</i>)-3-benzylidene-1-<i>tert</i>-butylpyrrolidine-2,5-dione,”
    <i>Acta Crystallographica Section C Structural Chemistry</i>, vol. 72, no. 6,
    pp. 504–508, 2016, doi: <a href="https://doi.org/10.1107/s2053229616008159">10.1107/s2053229616008159</a>.'
  mla: 'Schirmer, Marie-Luis, et al. “Highly Functionalized Alkenes Produced from
    Base-Free Organocatalytic Wittig Reactions: (<i>E</i>)-3-Benzylidenepyrrolidine-2,5-Dione,
    (<i>E</i>)-3-Benzylidene-1-Methylpyrrolidine-2,5-Dione and (<i>E</i>)-3-Benzylidene-1-<i>Tert</i>-Butylpyrrolidine-2,5-Dione.”
    <i>Acta Crystallographica Section C Structural Chemistry</i>, vol. 72, no. 6,
    International Union of Crystallography (IUCr), 2016, pp. 504–08, doi:<a href="https://doi.org/10.1107/s2053229616008159">10.1107/s2053229616008159</a>.'
  short: M.-L. Schirmer, A. Spannenberg, T. Werner, Acta Crystallographica Section
    C Structural Chemistry 72 (2016) 504–508.
date_created: 2023-01-22T21:03:23Z
date_updated: 2025-11-10T09:23:46Z
department:
- _id: '35'
- _id: '2'
- _id: '657'
doi: 10.1107/s2053229616008159
extern: '1'
intvolume: '        72'
issue: '6'
keyword:
- T2
language:
- iso: eng
page: 504-508
publication: Acta Crystallographica Section C Structural Chemistry
publication_identifier:
  issn:
  - 2053-2296
publication_status: published
publisher: International Union of Crystallography (IUCr)
status: public
title: 'Highly functionalized alkenes produced from base-free organocatalytic Wittig
  reactions: (<i>E</i>)-3-benzylidenepyrrolidine-2,5-dione, (<i>E</i>)-3-benzylidene-1-methylpyrrolidine-2,5-dione
  and (<i>E</i>)-3-benzylidene-1-<i>tert</i>-butylpyrrolidine-2,5-dione'
type: journal_article
user_id: '89271'
volume: 72
year: '2016'
...