Unveiling the Role of Base and Additive in the Ullmann-Type of Arene-Aryl C-C Coupling Reaction

Manjaly J. Ajitha; Fathima Pary; Toby L. Nelson; Djamaladdin G. Musaev

doi:10.1021/acscatal.8b00837

Unveiling the Role of Base and Additive in the Ullmann-Type of Arene-Aryl C-C Coupling Reaction

Manjaly J. Ajitha, Fathima Pary, Toby L. Nelson^*, Djamaladdin G. Musaev

^*Corresponding author for this work

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

25 Scopus citations

Abstract

The mechanism of Ullmann-type biaryl formation between benzo-[1,2-b:4,5-b′]dithiophene-1,1,5,5-tetraoxide (BDTT) and iodobenzene (ArI) was computationally studied in the presence of CuI, phenanthroline (Phen), K₃PO₄ (as a base), and Ag₂CO₃ (as an additive). It is shown that base and additive play critical roles in each step of the reaction, such as (a) the I-to-base exchange in complex (Phen)CuI, (b) substrate deprotonation via the acid-base mechanism, and (c) Ar-I activation and DBT-Ar coupling. It is shown that (a) the presence of sulfonyl oxygens in DBT is essential - it plays an anchoring role and brings substrate and base closer to each other. In the presence of K₃PO₄ and in the absence of additive Ag₂CO₃, the Ph-I activation and C-C coupling occurs via a Cu-mediated nucleophilic substitution mechanism and requires a significant free energy barrier. However, the addition of Ag₂CO₃ to the reaction mixture not only accelerates the DBT and PhI coupling by reducing the rate-limiting Ph-I activation barrier but also switches the mechanism of the reaction from a Cu-mediated nucleophilic substitution to a Ag(I)-promoted oxidative addition-reductive elimination. These findings are important for development of the next generation reaction conditions for Ullmann-type of coupling reactions.

Original language	English (US)
Pages (from-to)	4829-4837
Number of pages	9
Journal	ACS Catalysis
Volume	8
Issue number	6
DOIs	https://doi.org/10.1021/acscatal.8b00837
State	Published - Jun 1 2018

Bibliographical note

Funding Information:
This work was supported by the National Science Foundation under the CCI Center for Selective C−H Functionalization (CHE-1700982). We gratefully acknowledge NSF MRI-R2 grant (CHE-0958205 for D.G.M.) and the use of the resources of the Cherry Emerson Center for Scientific Computation, as well as Oklahoma State University Division of Institutional Diversity. Authors are thankful to Dr. Brandon Haines for help provided during the manuscript preparation.

Funding Information:
This work was supported by the National Science Foundation under the CCI Center for Selective C-H Functionalization (CHE-1700982). We gratefully acknowledge NSF MRI-R2 grant (CHE-0958205 for D.G.M.) and the use of the resources of the Cherry Emerson Center for Scientific Computation, as well as Oklahoma State University Division of Institutional Diversity. Authors are thankful to Dr. Brandon Haines for help provided during the manuscript preparation.

Publisher Copyright:
© 2018 American Chemical Society.

Keywords

additive effect
Ag(I)-promoted oxidative addition-reductive elimination
Cu-mediated nucleophilic substitution
DFT studies
Ullmann-coupling

ASJC Scopus subject areas

Catalysis
General Chemistry

Access to Document

10.1021/acscatal.8b00837

Cite this

@article{9aaf5bd9712543639d7569a0b4e3f2c7,

title = "Unveiling the Role of Base and Additive in the Ullmann-Type of Arene-Aryl C-C Coupling Reaction",

abstract = "The mechanism of Ullmann-type biaryl formation between benzo-[1,2-b:4,5-b′]dithiophene-1,1,5,5-tetraoxide (BDTT) and iodobenzene (ArI) was computationally studied in the presence of CuI, phenanthroline (Phen), K3PO4 (as a base), and Ag2CO3 (as an additive). It is shown that base and additive play critical roles in each step of the reaction, such as (a) the I-to-base exchange in complex (Phen)CuI, (b) substrate deprotonation via the acid-base mechanism, and (c) Ar-I activation and DBT-Ar coupling. It is shown that (a) the presence of sulfonyl oxygens in DBT is essential - it plays an anchoring role and brings substrate and base closer to each other. In the presence of K3PO4 and in the absence of additive Ag2CO3, the Ph-I activation and C-C coupling occurs via a Cu-mediated nucleophilic substitution mechanism and requires a significant free energy barrier. However, the addition of Ag2CO3 to the reaction mixture not only accelerates the DBT and PhI coupling by reducing the rate-limiting Ph-I activation barrier but also switches the mechanism of the reaction from a Cu-mediated nucleophilic substitution to a Ag(I)-promoted oxidative addition-reductive elimination. These findings are important for development of the next generation reaction conditions for Ullmann-type of coupling reactions.",

keywords = "additive effect, Ag(I)-promoted oxidative addition-reductive elimination, Cu-mediated nucleophilic substitution, DFT studies, Ullmann-coupling",

author = "Ajitha, {Manjaly J.} and Fathima Pary and Nelson, {Toby L.} and Musaev, {Djamaladdin G.}",

note = "Funding Information: This work was supported by the National Science Foundation under the CCI Center for Selective C−H Functionalization (CHE-1700982). We gratefully acknowledge NSF MRI-R2 grant (CHE-0958205 for D.G.M.) and the use of the resources of the Cherry Emerson Center for Scientific Computation, as well as Oklahoma State University Division of Institutional Diversity. Authors are thankful to Dr. Brandon Haines for help provided during the manuscript preparation. Funding Information: This work was supported by the National Science Foundation under the CCI Center for Selective C-H Functionalization (CHE-1700982). We gratefully acknowledge NSF MRI-R2 grant (CHE-0958205 for D.G.M.) and the use of the resources of the Cherry Emerson Center for Scientific Computation, as well as Oklahoma State University Division of Institutional Diversity. Authors are thankful to Dr. Brandon Haines for help provided during the manuscript preparation. Publisher Copyright: {\textcopyright} 2018 American Chemical Society.",

year = "2018",

month = jun,

day = "1",

doi = "10.1021/acscatal.8b00837",

language = "English (US)",

volume = "8",

pages = "4829--4837",

journal = "ACS Catalysis",

issn = "2155-5435",

publisher = "American Chemical Society",

number = "6",

}

TY - JOUR

T1 - Unveiling the Role of Base and Additive in the Ullmann-Type of Arene-Aryl C-C Coupling Reaction

AU - Ajitha, Manjaly J.

AU - Pary, Fathima

AU - Nelson, Toby L.

AU - Musaev, Djamaladdin G.

N1 - Funding Information: This work was supported by the National Science Foundation under the CCI Center for Selective C−H Functionalization (CHE-1700982). We gratefully acknowledge NSF MRI-R2 grant (CHE-0958205 for D.G.M.) and the use of the resources of the Cherry Emerson Center for Scientific Computation, as well as Oklahoma State University Division of Institutional Diversity. Authors are thankful to Dr. Brandon Haines for help provided during the manuscript preparation. Funding Information: This work was supported by the National Science Foundation under the CCI Center for Selective C-H Functionalization (CHE-1700982). We gratefully acknowledge NSF MRI-R2 grant (CHE-0958205 for D.G.M.) and the use of the resources of the Cherry Emerson Center for Scientific Computation, as well as Oklahoma State University Division of Institutional Diversity. Authors are thankful to Dr. Brandon Haines for help provided during the manuscript preparation. Publisher Copyright: © 2018 American Chemical Society.

PY - 2018/6/1

Y1 - 2018/6/1

N2 - The mechanism of Ullmann-type biaryl formation between benzo-[1,2-b:4,5-b′]dithiophene-1,1,5,5-tetraoxide (BDTT) and iodobenzene (ArI) was computationally studied in the presence of CuI, phenanthroline (Phen), K3PO4 (as a base), and Ag2CO3 (as an additive). It is shown that base and additive play critical roles in each step of the reaction, such as (a) the I-to-base exchange in complex (Phen)CuI, (b) substrate deprotonation via the acid-base mechanism, and (c) Ar-I activation and DBT-Ar coupling. It is shown that (a) the presence of sulfonyl oxygens in DBT is essential - it plays an anchoring role and brings substrate and base closer to each other. In the presence of K3PO4 and in the absence of additive Ag2CO3, the Ph-I activation and C-C coupling occurs via a Cu-mediated nucleophilic substitution mechanism and requires a significant free energy barrier. However, the addition of Ag2CO3 to the reaction mixture not only accelerates the DBT and PhI coupling by reducing the rate-limiting Ph-I activation barrier but also switches the mechanism of the reaction from a Cu-mediated nucleophilic substitution to a Ag(I)-promoted oxidative addition-reductive elimination. These findings are important for development of the next generation reaction conditions for Ullmann-type of coupling reactions.

AB - The mechanism of Ullmann-type biaryl formation between benzo-[1,2-b:4,5-b′]dithiophene-1,1,5,5-tetraoxide (BDTT) and iodobenzene (ArI) was computationally studied in the presence of CuI, phenanthroline (Phen), K3PO4 (as a base), and Ag2CO3 (as an additive). It is shown that base and additive play critical roles in each step of the reaction, such as (a) the I-to-base exchange in complex (Phen)CuI, (b) substrate deprotonation via the acid-base mechanism, and (c) Ar-I activation and DBT-Ar coupling. It is shown that (a) the presence of sulfonyl oxygens in DBT is essential - it plays an anchoring role and brings substrate and base closer to each other. In the presence of K3PO4 and in the absence of additive Ag2CO3, the Ph-I activation and C-C coupling occurs via a Cu-mediated nucleophilic substitution mechanism and requires a significant free energy barrier. However, the addition of Ag2CO3 to the reaction mixture not only accelerates the DBT and PhI coupling by reducing the rate-limiting Ph-I activation barrier but also switches the mechanism of the reaction from a Cu-mediated nucleophilic substitution to a Ag(I)-promoted oxidative addition-reductive elimination. These findings are important for development of the next generation reaction conditions for Ullmann-type of coupling reactions.

KW - additive effect

KW - Ag(I)-promoted oxidative addition-reductive elimination

KW - Cu-mediated nucleophilic substitution

KW - DFT studies

KW - Ullmann-coupling

UR - http://www.scopus.com/inward/record.url?scp=85048016634&partnerID=8YFLogxK

U2 - 10.1021/acscatal.8b00837

DO - 10.1021/acscatal.8b00837

M3 - Article

AN - SCOPUS:85048016634

SN - 2155-5435

VL - 8

SP - 4829

EP - 4837

JO - ACS Catalysis

JF - ACS Catalysis

IS - 6

ER -

Unveiling the Role of Base and Additive in the Ullmann-Type of Arene-Aryl C-C Coupling Reaction

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this