Details
| Original language | English |
|---|---|
| Pages (from-to) | 2095-2110 |
| Number of pages | 16 |
| Journal | Organometallics |
| Volume | 37 |
| Issue number | 13 |
| Publication status | Published - 26 Jun 2018 |
Abstract
The catalytic ortho-alkenylation at ferrocene has been investigated with Cp∗Co(CO)I2 as the catalyst for some nitrogen ortho-directing groups (ODGs). The reaction conditions were optimized starting from 2-ferrocenylpyridine, and a number of terminal arylethynes gave preferentially the 2,5-dialkenylation products in up to 94% yield. In most cases the 2-monoalkenylation products were not obtained, although there are exceptions with formyl- and thioacetyl-substituted arylethynes and ferrocenylethyne. When 1-phenylpropyne was used, the dialkenylation took place with high selectivity. Use of 1-ferrocenylisoquinoline resulted in moderate yields with poor selectivity for the mono- or dialkenylation. With N,N-dimethylferrocenylcarboxamide, however, very high selectivity for monoalkenylation was observed. Products were obtained in up to 90% yield; in only one case the dialkenylation was product observed in trace amounts. All products were characterized spectroscopically, including four crystal structure analyses. The results are explained by the steric hindrance of the N,N-diemethylcarbamoyl ODG when the conformation necessary for a second alkenylation is adopted. In summary, ODGs for the selective cobalt-catalyzed mono- or dialkenylation have been identified.
ASJC Scopus subject areas
- Chemistry(all)
- Physical and Theoretical Chemistry
- Chemistry(all)
- Organic Chemistry
- Chemistry(all)
- Inorganic Chemistry
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In: Organometallics, Vol. 37, No. 13, 26.06.2018, p. 2095-2110.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Cp∗Co(CO)I2 as Catalyst for Ortho-C,H Activation at Ferrocene
T2 - ODG-Dependent Preference for 2-Mono- or 2,5-Dialkenylation
AU - Schmiel, David
AU - Gathy, Robert
AU - Butenschön, Holger
PY - 2018/6/26
Y1 - 2018/6/26
N2 - The catalytic ortho-alkenylation at ferrocene has been investigated with Cp∗Co(CO)I2 as the catalyst for some nitrogen ortho-directing groups (ODGs). The reaction conditions were optimized starting from 2-ferrocenylpyridine, and a number of terminal arylethynes gave preferentially the 2,5-dialkenylation products in up to 94% yield. In most cases the 2-monoalkenylation products were not obtained, although there are exceptions with formyl- and thioacetyl-substituted arylethynes and ferrocenylethyne. When 1-phenylpropyne was used, the dialkenylation took place with high selectivity. Use of 1-ferrocenylisoquinoline resulted in moderate yields with poor selectivity for the mono- or dialkenylation. With N,N-dimethylferrocenylcarboxamide, however, very high selectivity for monoalkenylation was observed. Products were obtained in up to 90% yield; in only one case the dialkenylation was product observed in trace amounts. All products were characterized spectroscopically, including four crystal structure analyses. The results are explained by the steric hindrance of the N,N-diemethylcarbamoyl ODG when the conformation necessary for a second alkenylation is adopted. In summary, ODGs for the selective cobalt-catalyzed mono- or dialkenylation have been identified.
AB - The catalytic ortho-alkenylation at ferrocene has been investigated with Cp∗Co(CO)I2 as the catalyst for some nitrogen ortho-directing groups (ODGs). The reaction conditions were optimized starting from 2-ferrocenylpyridine, and a number of terminal arylethynes gave preferentially the 2,5-dialkenylation products in up to 94% yield. In most cases the 2-monoalkenylation products were not obtained, although there are exceptions with formyl- and thioacetyl-substituted arylethynes and ferrocenylethyne. When 1-phenylpropyne was used, the dialkenylation took place with high selectivity. Use of 1-ferrocenylisoquinoline resulted in moderate yields with poor selectivity for the mono- or dialkenylation. With N,N-dimethylferrocenylcarboxamide, however, very high selectivity for monoalkenylation was observed. Products were obtained in up to 90% yield; in only one case the dialkenylation was product observed in trace amounts. All products were characterized spectroscopically, including four crystal structure analyses. The results are explained by the steric hindrance of the N,N-diemethylcarbamoyl ODG when the conformation necessary for a second alkenylation is adopted. In summary, ODGs for the selective cobalt-catalyzed mono- or dialkenylation have been identified.
UR - http://www.scopus.com/inward/record.url?scp=85049748583&partnerID=8YFLogxK
U2 - 10.1021/acs.organomet.8b00243
DO - 10.1021/acs.organomet.8b00243
M3 - Article
AN - SCOPUS:85049748583
VL - 37
SP - 2095
EP - 2110
JO - Organometallics
JF - Organometallics
SN - 0276-7333
IS - 13
ER -