Carbocyclic cis-[1.1.1]-tris-σ-homobenzenes - Syntheses by triple epoxide → cyclopropane conversions, structural data, [σ2s+σ2s+σ2s] cycloreversions

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Carbocyclic cis-[1.1.1]-tris-σ-homobenzenes - Syntheses by triple epoxide → cyclopropane conversions, structural data, [σ2s+σ2s+σ2s] cycloreversions. / Rücker, Christoph; Müller-Bötticher, Hermann; Braschwitz, Wolf-Dieter et al.
in: Liebigs Annalen - recueil, Jahrgang 1997, Nr. 5, 01.05.1997, S. 967-989.

Publikation: Beiträge in ZeitschriftenZeitschriftenaufsätzeForschungbegutachtet

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Rücker C, Müller-Bötticher H, Braschwitz WD, Prinzbach H, Reifenstahl U, Irngartinger H. Carbocyclic cis-[1.1.1]-tris-σ-homobenzenes - Syntheses by triple epoxide → cyclopropane conversions, structural data, [σ2s+σ2s+σ2s] cycloreversions. Liebigs Annalen - recueil. 1997 Mai 1;1997(5):967-989. doi: 10.1002/jlac.199719970528

Bibtex

@article{f2dfcc20662c4b4dba73c5eca0463010,
title = "Carbocyclic cis-[1.1.1]-tris-σ-homobenzenes - Syntheses by triple epoxide → cyclopropane conversions, structural data, [σ2s+σ2s+σ2s] cycloreversions",
abstract = "By triple epoxide → cyclopropane transformation starting from cis-benzene trioxide the 3α,6α,9α-tris(TIPS-ethynyl) (1b), -tris(alkoxycarbonyl) (1d, e), -tricyano (1f), and -tris(ammoniomethyl) (1j) derivatives of the still elusive parent cis-[1.1.1]-tris-σ-homobenzene (1a) have been synthesized. Out of a number of carbon nucleophiles tested, a weakly basic mixed cyanocuprate of Li-TIPS-propyne proved the reagent of choice: Eliminations were largely avoided, the scyllo [*]-2,4,6-tris(TIPS-propargyl)cyclohexane-1,3,5-triol (13a), obtained in a stereoselective one-pot threefold epoxide opening (up to 69%), allowed the pertinent functional group manipulations. The selectivity of the base-induced triple cyclopropane ring closure in the flexible cyclohexane precursors strongly depends on the activating groups and is promoted by fixation of the {"}all-axial{"} conformation as an adamantoid orthophosphate. The ΔG ≠ values determined for the generally neat 3σ → 3π isomerizations [28.5 (1e), 29.0 (1f), 22.6 (1j) kcal mol -1] are in line with concerted reaction courses ([σ2s+σ2s+σ2s]). For the trinitrile 1f an X-ray structure analysis confirmed a nearly planar cyclohexane ring and a relatively large cyclohexane/cyclopropane interplanary angle (113°).",
keywords = "Chemistry, cis-[1.1.1]-Tris-σ-homobenzenes, Substituent effects, [σ2s+σ2s+σ2s] Cycloreversions",
author = "Christoph R{\"u}cker and Hermann M{\"u}ller-B{\"o}tticher and Wolf-Dieter Braschwitz and Horst Prinzbach and Uwe Reifenstahl and Hermann Irngartinger",
year = "1997",
month = may,
day = "1",
doi = "10.1002/jlac.199719970528",
language = "English",
volume = "1997",
pages = "967--989",
journal = "Liebigs Annalen - recueil",
issn = "0947-3440",
publisher = "VCH Verlagsgesellschaft",
number = "5",

}

RIS

TY - JOUR

T1 - Carbocyclic cis-[1.1.1]-tris-σ-homobenzenes - Syntheses by triple epoxide → cyclopropane conversions, structural data, [σ2s+σ2s+σ2s] cycloreversions

AU - Rücker, Christoph

AU - Müller-Bötticher, Hermann

AU - Braschwitz, Wolf-Dieter

AU - Prinzbach, Horst

AU - Reifenstahl, Uwe

AU - Irngartinger, Hermann

PY - 1997/5/1

Y1 - 1997/5/1

N2 - By triple epoxide → cyclopropane transformation starting from cis-benzene trioxide the 3α,6α,9α-tris(TIPS-ethynyl) (1b), -tris(alkoxycarbonyl) (1d, e), -tricyano (1f), and -tris(ammoniomethyl) (1j) derivatives of the still elusive parent cis-[1.1.1]-tris-σ-homobenzene (1a) have been synthesized. Out of a number of carbon nucleophiles tested, a weakly basic mixed cyanocuprate of Li-TIPS-propyne proved the reagent of choice: Eliminations were largely avoided, the scyllo [*]-2,4,6-tris(TIPS-propargyl)cyclohexane-1,3,5-triol (13a), obtained in a stereoselective one-pot threefold epoxide opening (up to 69%), allowed the pertinent functional group manipulations. The selectivity of the base-induced triple cyclopropane ring closure in the flexible cyclohexane precursors strongly depends on the activating groups and is promoted by fixation of the "all-axial" conformation as an adamantoid orthophosphate. The ΔG ≠ values determined for the generally neat 3σ → 3π isomerizations [28.5 (1e), 29.0 (1f), 22.6 (1j) kcal mol -1] are in line with concerted reaction courses ([σ2s+σ2s+σ2s]). For the trinitrile 1f an X-ray structure analysis confirmed a nearly planar cyclohexane ring and a relatively large cyclohexane/cyclopropane interplanary angle (113°).

AB - By triple epoxide → cyclopropane transformation starting from cis-benzene trioxide the 3α,6α,9α-tris(TIPS-ethynyl) (1b), -tris(alkoxycarbonyl) (1d, e), -tricyano (1f), and -tris(ammoniomethyl) (1j) derivatives of the still elusive parent cis-[1.1.1]-tris-σ-homobenzene (1a) have been synthesized. Out of a number of carbon nucleophiles tested, a weakly basic mixed cyanocuprate of Li-TIPS-propyne proved the reagent of choice: Eliminations were largely avoided, the scyllo [*]-2,4,6-tris(TIPS-propargyl)cyclohexane-1,3,5-triol (13a), obtained in a stereoselective one-pot threefold epoxide opening (up to 69%), allowed the pertinent functional group manipulations. The selectivity of the base-induced triple cyclopropane ring closure in the flexible cyclohexane precursors strongly depends on the activating groups and is promoted by fixation of the "all-axial" conformation as an adamantoid orthophosphate. The ΔG ≠ values determined for the generally neat 3σ → 3π isomerizations [28.5 (1e), 29.0 (1f), 22.6 (1j) kcal mol -1] are in line with concerted reaction courses ([σ2s+σ2s+σ2s]). For the trinitrile 1f an X-ray structure analysis confirmed a nearly planar cyclohexane ring and a relatively large cyclohexane/cyclopropane interplanary angle (113°).

KW - Chemistry

KW - cis-[1.1.1]-Tris-σ-homobenzenes

KW - Substituent effects

KW - [σ2s+σ2s+σ2s] Cycloreversions

UR - http://www.scopus.com/inward/record.url?scp=0345970701&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/62c3684d-30b2-34a8-a4a9-30ffb3d7f993/

U2 - 10.1002/jlac.199719970528

DO - 10.1002/jlac.199719970528

M3 - Journal articles

VL - 1997

SP - 967

EP - 989

JO - Liebigs Annalen - recueil

JF - Liebigs Annalen - recueil

SN - 0947-3440

IS - 5

ER -

DOI