Ring-Closing Metathesis of Co2(CO)6−Alkyne Complexes for the Synthesis of 11-Membered Dienediynes: Overcoming Thermodynamic Barriers

Наталья Александровна Данилкина, Анна Геннадьевна Ляпунова, Александр Феодосиевич Хлебников, Галина Леонидовна Старова, Stefan Brase, Ирина Анатольевна Балова

Research output

Abstract

The feasibility of ring-closing metathesis (RCM) as a
synthetic entry to 10- and 11-membered dienediynes fused to a
benzothiophene core was explored by experimental and theoretical
investigations. An established sequence of iodocyclization of o-(buta-1,3-
diynyl)thioanisoles followed by Sonogashira coupling to form diethynylbenzothiophenes
was used to synthesize terminal benzothiophene-fused
enediyne diolefins as substrates for RCM. Encountering an unexpected
lack of reactivity of these substrates under standard RCM conditions, we
applied DFT calculations to reveal that the underlying cause was a positive
change in Gibbs free energy. The change in Gibbs free energy was also found
to be positive for RCM of indole- and benzannulated terminal diolefins when
affording smaller than 12-membered rings. We found that modification of the
enediyne−diolefin substrate as the Co2(CO)6−alkyne complex allowed the
target benzothiophene-fused 11-membered dienediyne to be obtained via
RCM; the alkyne complexation strategy therefore provides one valid technique for overcoming challenges to macrocyclization of
this kind.
Original languageEnglish
Pages (from-to)5546-5555
Number of pages10
JournalJournal of Organic Chemistry
Volume80
DOIs
Publication statusPublished - 2015

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Alkadienes
Thermodynamics
Gibbs free energy
Substrates
Alkynes
Complexation
Discrete Fourier transforms
benzothiophene

Cite this

@article{ba0a23fbdfb941b5abb4dcbd00562c4b,
title = "Ring-Closing Metathesis of Co2(CO)6−Alkyne Complexes for the Synthesis of 11-Membered Dienediynes: Overcoming Thermodynamic Barriers",
abstract = "The feasibility of ring-closing metathesis (RCM) as asynthetic entry to 10- and 11-membered dienediynes fused to abenzothiophene core was explored by experimental and theoreticalinvestigations. An established sequence of iodocyclization of o-(buta-1,3-diynyl)thioanisoles followed by Sonogashira coupling to form diethynylbenzothiopheneswas used to synthesize terminal benzothiophene-fusedenediyne diolefins as substrates for RCM. Encountering an unexpectedlack of reactivity of these substrates under standard RCM conditions, weapplied DFT calculations to reveal that the underlying cause was a positivechange in Gibbs free energy. The change in Gibbs free energy was also foundto be positive for RCM of indole- and benzannulated terminal diolefins whenaffording smaller than 12-membered rings. We found that modification of theenediyne−diolefin substrate as the Co2(CO)6−alkyne complex allowed thetarget benzothiophene-fused 11-membered dienediyne to be obtained viaRCM; the alkyne complexation strategy therefore provides one valid technique for overcoming challenges to macrocyclization ofthis kind.",
author = "Данилкина, {Наталья Александровна} and Ляпунова, {Анна Геннадьевна} and Хлебников, {Александр Феодосиевич} and Старова, {Галина Леонидовна} and {Stefan Brase} and Балова, {Ирина Анатольевна}",
year = "2015",
doi = "http://dx.doi.org/10.1021/acs.joc.5b00409",
language = "English",
volume = "80",
pages = "5546--5555",
journal = "Journal of Organic Chemistry",
issn = "0022-3263",
publisher = "American Chemical Society",

}

TY - JOUR

T1 - Ring-Closing Metathesis of Co2(CO)6−Alkyne Complexes for the Synthesis of 11-Membered Dienediynes: Overcoming Thermodynamic Barriers

AU - Данилкина, Наталья Александровна

AU - Ляпунова, Анна Геннадьевна

AU - Хлебников, Александр Феодосиевич

AU - Старова, Галина Леонидовна

AU - Stefan Brase

AU - Балова, Ирина Анатольевна

PY - 2015

Y1 - 2015

N2 - The feasibility of ring-closing metathesis (RCM) as asynthetic entry to 10- and 11-membered dienediynes fused to abenzothiophene core was explored by experimental and theoreticalinvestigations. An established sequence of iodocyclization of o-(buta-1,3-diynyl)thioanisoles followed by Sonogashira coupling to form diethynylbenzothiopheneswas used to synthesize terminal benzothiophene-fusedenediyne diolefins as substrates for RCM. Encountering an unexpectedlack of reactivity of these substrates under standard RCM conditions, weapplied DFT calculations to reveal that the underlying cause was a positivechange in Gibbs free energy. The change in Gibbs free energy was also foundto be positive for RCM of indole- and benzannulated terminal diolefins whenaffording smaller than 12-membered rings. We found that modification of theenediyne−diolefin substrate as the Co2(CO)6−alkyne complex allowed thetarget benzothiophene-fused 11-membered dienediyne to be obtained viaRCM; the alkyne complexation strategy therefore provides one valid technique for overcoming challenges to macrocyclization ofthis kind.

AB - The feasibility of ring-closing metathesis (RCM) as asynthetic entry to 10- and 11-membered dienediynes fused to abenzothiophene core was explored by experimental and theoreticalinvestigations. An established sequence of iodocyclization of o-(buta-1,3-diynyl)thioanisoles followed by Sonogashira coupling to form diethynylbenzothiopheneswas used to synthesize terminal benzothiophene-fusedenediyne diolefins as substrates for RCM. Encountering an unexpectedlack of reactivity of these substrates under standard RCM conditions, weapplied DFT calculations to reveal that the underlying cause was a positivechange in Gibbs free energy. The change in Gibbs free energy was also foundto be positive for RCM of indole- and benzannulated terminal diolefins whenaffording smaller than 12-membered rings. We found that modification of theenediyne−diolefin substrate as the Co2(CO)6−alkyne complex allowed thetarget benzothiophene-fused 11-membered dienediyne to be obtained viaRCM; the alkyne complexation strategy therefore provides one valid technique for overcoming challenges to macrocyclization ofthis kind.

U2 - http://dx.doi.org/10.1021/acs.joc.5b00409

DO - http://dx.doi.org/10.1021/acs.joc.5b00409

M3 - Article

VL - 80

SP - 5546

EP - 5555

JO - Journal of Organic Chemistry

JF - Journal of Organic Chemistry

SN - 0022-3263

ER -