Abstract
Polymethyl substituted [3.3]metacyclophanes (MCPs) 4 a–d, were synthesized by the TosMIC coupling method followed by Wolff–Kishner reduction of the corresponding polymethyl-substituted [3.3]MCP-2,11-diones (3 a–d). 1H NMR spectroscopy reveals that both 5,6,7,14,16-pentamethyl[3.3]MCP-2,11-diones (3 a and 3 b) undergo conformational changes relative to the NMR time scale in solution at room temperature but that the anti conformer is preferred. Reduced 5,6,7,14,16-pentamethyl[3.3]MCP (4 a and 4 b) adopt fixed syn–conformations in solution at room temperature. X-ray analysis showed that in the solid state, 5,6,7,14,15,16-hexamethyl[3.3]MCP-2,11-dione 3 a adopts the anti-conformation and reduced 5,6,7,14,16-pentamethyl[3.3]MCP-2,11-diones 4 b adopts a syn-(chair-chair) conformation. A series of electrophilic substitution reactions such as formylation, acetylation and nitration were carried out with 5,6,7,14,16-pentamethyl[3.3]MCP 4 b to study their conformational isomers. The formyl, acetyl and nitro derivatives of 5,6,7,14,16-pentamethyl[3.3]MCP are fixed to adopt syn-conformations in solution at room temperature. The conformational isomers of the metacyclophanes and derivatives obtained from density functional theory (DFT) methods were used to estimate the total energies and energy minimized structures of the different conformations.
| Original language | English |
|---|---|
| Pages (from-to) | 7255-7262 |
| Number of pages | 8 |
| Journal | ChemistrySelect |
| Volume | 2 |
| Issue number | 24 |
| DOIs | |
| Publication status | Published - Jan 1 2017 |
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All Science Journal Classification (ASJC) codes
- Chemistry(all)
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Synthesis, Conformational Properties and DFT Computational Studies of Polymethyl-Substituted [3.3]Metacyclophanes. / Islam, Md Monarul; Akther, Thamina; Rahman, Shofiur; Georghiou, Paris E.; Matsumoto, Taisuke; Tanaka, Junji; Redshaw, Carl; Yamato, Takehiko.
In: ChemistrySelect, Vol. 2, No. 24, 01.01.2017, p. 7255-7262.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Synthesis, Conformational Properties and DFT Computational Studies of Polymethyl-Substituted [3.3]Metacyclophanes
AU - Islam, Md Monarul
AU - Akther, Thamina
AU - Rahman, Shofiur
AU - Georghiou, Paris E.
AU - Matsumoto, Taisuke
AU - Tanaka, Junji
AU - Redshaw, Carl
AU - Yamato, Takehiko
PY - 2017/1/1
Y1 - 2017/1/1
N2 - Polymethyl substituted [3.3]metacyclophanes (MCPs) 4 a–d, were synthesized by the TosMIC coupling method followed by Wolff–Kishner reduction of the corresponding polymethyl-substituted [3.3]MCP-2,11-diones (3 a–d). 1H NMR spectroscopy reveals that both 5,6,7,14,16-pentamethyl[3.3]MCP-2,11-diones (3 a and 3 b) undergo conformational changes relative to the NMR time scale in solution at room temperature but that the anti conformer is preferred. Reduced 5,6,7,14,16-pentamethyl[3.3]MCP (4 a and 4 b) adopt fixed syn–conformations in solution at room temperature. X-ray analysis showed that in the solid state, 5,6,7,14,15,16-hexamethyl[3.3]MCP-2,11-dione 3 a adopts the anti-conformation and reduced 5,6,7,14,16-pentamethyl[3.3]MCP-2,11-diones 4 b adopts a syn-(chair-chair) conformation. A series of electrophilic substitution reactions such as formylation, acetylation and nitration were carried out with 5,6,7,14,16-pentamethyl[3.3]MCP 4 b to study their conformational isomers. The formyl, acetyl and nitro derivatives of 5,6,7,14,16-pentamethyl[3.3]MCP are fixed to adopt syn-conformations in solution at room temperature. The conformational isomers of the metacyclophanes and derivatives obtained from density functional theory (DFT) methods were used to estimate the total energies and energy minimized structures of the different conformations.
AB - Polymethyl substituted [3.3]metacyclophanes (MCPs) 4 a–d, were synthesized by the TosMIC coupling method followed by Wolff–Kishner reduction of the corresponding polymethyl-substituted [3.3]MCP-2,11-diones (3 a–d). 1H NMR spectroscopy reveals that both 5,6,7,14,16-pentamethyl[3.3]MCP-2,11-diones (3 a and 3 b) undergo conformational changes relative to the NMR time scale in solution at room temperature but that the anti conformer is preferred. Reduced 5,6,7,14,16-pentamethyl[3.3]MCP (4 a and 4 b) adopt fixed syn–conformations in solution at room temperature. X-ray analysis showed that in the solid state, 5,6,7,14,15,16-hexamethyl[3.3]MCP-2,11-dione 3 a adopts the anti-conformation and reduced 5,6,7,14,16-pentamethyl[3.3]MCP-2,11-diones 4 b adopts a syn-(chair-chair) conformation. A series of electrophilic substitution reactions such as formylation, acetylation and nitration were carried out with 5,6,7,14,16-pentamethyl[3.3]MCP 4 b to study their conformational isomers. The formyl, acetyl and nitro derivatives of 5,6,7,14,16-pentamethyl[3.3]MCP are fixed to adopt syn-conformations in solution at room temperature. The conformational isomers of the metacyclophanes and derivatives obtained from density functional theory (DFT) methods were used to estimate the total energies and energy minimized structures of the different conformations.
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U2 - 10.1002/slct.201701243
DO - 10.1002/slct.201701243
M3 - Article
AN - SCOPUS:85038850754
VL - 2
SP - 7255
EP - 7262
JO - ChemistrySelect
JF - ChemistrySelect
SN - 2365-6549
IS - 24
ER -