Interplay of twisting and folding in overcrowded heteromerous bistricyclic aromatic enes

Amalia Levy; P. Ulrich Biedermann; Israel Agranat

doi:10.1021/ol005827c

Interplay of twisting and folding in overcrowded heteromerous bistricyclic aromatic enes

Amalia Levy, P. Ulrich Biedermann, Israel Agranat

Research output: Contribution to journal › Article › peer-review

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Abstract

(Formula presented) Flourenylidenexanthenes 5-7 were synthesized by 2-fold extrusion diazo-thione couplings. 7 exhibited yellow crystals and purple (560 nm) solutions. ¹H NMR of 5 and 7 indicated subtle equilibria twisted (t) ⇌ anti-folded (a) major/minor conformations. ¹³C DNMR of 6 gave ΔG_c‡(enantiomerization/inversion) = 26.5 kJ/mol and ΔG_c‡(E,Z-topomerization) = 82.0 kJ/mol. PM3 calculations of 5 revealed minima a, t, ts (twisted/syn-folded), ΔΔH_f^o = 0.0, 14.1, 15.6 kJ/mol, and transition states [t-ts], [a-ts], [t_⊥], [a-a*], ΔΔH_f^o = 16.3, 17.4, 82.2, 99.3 kJ/mol.

Original language	English
Pages (from-to)	1811-1814
Number of pages	4
Journal	Organic Letters
Volume	2
Issue number	13
DOIs	https://doi.org/10.1021/ol005827c
State	Published - 29 Jun 2000
Externally published	Yes

ASJC Scopus subject areas

Biochemistry
Physical and Theoretical Chemistry
Organic Chemistry

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10.1021/ol005827c

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title = "Interplay of twisting and folding in overcrowded heteromerous bistricyclic aromatic enes",

abstract = "(Formula presented) Flourenylidenexanthenes 5-7 were synthesized by 2-fold extrusion diazo-thione couplings. 7 exhibited yellow crystals and purple (560 nm) solutions. 1H NMR of 5 and 7 indicated subtle equilibria twisted (t) ⇌ anti-folded (a) major/minor conformations. 13C DNMR of 6 gave ΔGc‡(enantiomerization/inversion) = 26.5 kJ/mol and ΔGc‡(E,Z-topomerization) = 82.0 kJ/mol. PM3 calculations of 5 revealed minima a, t, ts (twisted/syn-folded), ΔΔHfo = 0.0, 14.1, 15.6 kJ/mol, and transition states [t-ts], [a-ts], [t⊥], [a-a*], ΔΔHfo = 16.3, 17.4, 82.2, 99.3 kJ/mol.",

author = "Amalia Levy and Biedermann, {P. Ulrich} and Israel Agranat",

year = "2000",

month = jun,

day = "29",

doi = "10.1021/ol005827c",

language = "English",

volume = "2",

pages = "1811--1814",

journal = "Organic Letters",

issn = "1523-7060",

publisher = "American Chemical Society",

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TY - JOUR

T1 - Interplay of twisting and folding in overcrowded heteromerous bistricyclic aromatic enes

AU - Levy, Amalia

AU - Biedermann, P. Ulrich

AU - Agranat, Israel

PY - 2000/6/29

Y1 - 2000/6/29

N2 - (Formula presented) Flourenylidenexanthenes 5-7 were synthesized by 2-fold extrusion diazo-thione couplings. 7 exhibited yellow crystals and purple (560 nm) solutions. 1H NMR of 5 and 7 indicated subtle equilibria twisted (t) ⇌ anti-folded (a) major/minor conformations. 13C DNMR of 6 gave ΔGc‡(enantiomerization/inversion) = 26.5 kJ/mol and ΔGc‡(E,Z-topomerization) = 82.0 kJ/mol. PM3 calculations of 5 revealed minima a, t, ts (twisted/syn-folded), ΔΔHfo = 0.0, 14.1, 15.6 kJ/mol, and transition states [t-ts], [a-ts], [t⊥], [a-a*], ΔΔHfo = 16.3, 17.4, 82.2, 99.3 kJ/mol.

AB - (Formula presented) Flourenylidenexanthenes 5-7 were synthesized by 2-fold extrusion diazo-thione couplings. 7 exhibited yellow crystals and purple (560 nm) solutions. 1H NMR of 5 and 7 indicated subtle equilibria twisted (t) ⇌ anti-folded (a) major/minor conformations. 13C DNMR of 6 gave ΔGc‡(enantiomerization/inversion) = 26.5 kJ/mol and ΔGc‡(E,Z-topomerization) = 82.0 kJ/mol. PM3 calculations of 5 revealed minima a, t, ts (twisted/syn-folded), ΔΔHfo = 0.0, 14.1, 15.6 kJ/mol, and transition states [t-ts], [a-ts], [t⊥], [a-a*], ΔΔHfo = 16.3, 17.4, 82.2, 99.3 kJ/mol.

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U2 - 10.1021/ol005827c

DO - 10.1021/ol005827c

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SN - 1523-7060

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EP - 1814

JO - Organic Letters

JF - Organic Letters

IS - 13

ER -

Interplay of twisting and folding in overcrowded heteromerous bistricyclic aromatic enes

Abstract

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