(CDC)-Rhodium-catalyzed hydroallylation of vinylarenes and 1,3-dienes with allyltrifluoroborates

Justin S. Marcum; Tia N. Cervarich; Rajith S. Manan; Courtney C. Roberts; Simon J. Meek

doi:10.1021/acscatal.9b01579

(CDC)-Rhodium-catalyzed hydroallylation of vinylarenes and 1,3-dienes with allyltrifluoroborates

Justin S. Marcum, Tia N. Cervarich, Rajith S. Manan, Courtney C. Roberts, Simon J. Meek

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

23 Scopus citations

Abstract

Catalytic site-selective hydroallylation of vinyl arenes and 1,3-dienes is reported. Transformations are promoted by a readily accessible bidentate carbodicarbene-rhodium complex and involve commercially available allyltrifluoroborates and an alcohol. The reaction is applicable to vinyl arenes and aryl-or alkyl-substituted 1,3-dienes (30 examples). Allyl addition products are generated in 40-78% yield and in up to >98:2 site selectivity. Reaction outcomes are consistent with the intermediacy of a Rh(III)-hydride generated by protonation of Rh(I) by an acid. A number of key mechanistic details of the reaction are presented: (1) Deuterium scrambling into the product and starting alkene indicates reversible Rh(III)-H migratory insertion. (2) A large primary kinetic isotope effect is observed. (3) With substituted allyltrifluoroborates (e.g., crotyl-BF₃K) mixtures of site isomers are generated as a result of transmetalation followed by Rh-(allyl) complex equilibration, consequently disproving outer-sphere addition of the allyl nucleophile to Rh(III)-(η³-allyl). (4) Stereochemical analysis of a cyclohexadiene allyl addition product supports a syn Rh(III)-hydride addition. (5) A Hammett plot shows a negative slope. Finally, utility is highlighted by a iodocyclization and cross metathesis.

Original language	English (US)
Pages (from-to)	5881-5889
Number of pages	9
Journal	ACS Catalysis
Volume	9
Issue number	7
DOIs	https://doi.org/10.1021/acscatal.9b01579
State	Published - May 22 2019
Externally published	Yes

Bibliographical note

Funding Information:
Financial support was provided by the NSF (CHE-1665125) and the University of North Carolina at Chapel Hill. J.S.M. is grateful for a Burroughs-Welcome fellowship from the UNC Chemistry Department. We thank the University of North Carolina's Department of Chemistry Mass Spectrometry Core Laboratory for their assistance with mass spectrometry analysis. This material is based upon work supported by the National Science Foundation under Grant No. (CHE1726291).

Funding Information:
Financial support was provided by the NSF (CHE-1665125) and the University of North Carolina at Chapel Hill. J.S.M. is grateful for a Burroughs-Welcome fellowship from the UNC Chemistry Department. We thank the University of North Carolina’s Department of Chemistry Mass Spectrometry Core Laboratory for their assistance with mass spectrometry analysis. This material is based upon work supported by the National Science Foundation under Grant No. (CHE1726291).

Publisher Copyright:
© 2019 American Chemical Society.

Keywords

alkene
allyltrifluoroborates
carbodicarbene ligands
hydroallylation
rhodium catalysis

Access

10.1021/acscatal.9b01579

OpenUrl availability

Full text

Cite this

@article{1a403b9d00aa41799d09fe74900675bf,

title = "(CDC)-Rhodium-catalyzed hydroallylation of vinylarenes and 1,3-dienes with allyltrifluoroborates",

abstract = "Catalytic site-selective hydroallylation of vinyl arenes and 1,3-dienes is reported. Transformations are promoted by a readily accessible bidentate carbodicarbene-rhodium complex and involve commercially available allyltrifluoroborates and an alcohol. The reaction is applicable to vinyl arenes and aryl-or alkyl-substituted 1,3-dienes (30 examples). Allyl addition products are generated in 40-78% yield and in up to >98:2 site selectivity. Reaction outcomes are consistent with the intermediacy of a Rh(III)-hydride generated by protonation of Rh(I) by an acid. A number of key mechanistic details of the reaction are presented: (1) Deuterium scrambling into the product and starting alkene indicates reversible Rh(III)-H migratory insertion. (2) A large primary kinetic isotope effect is observed. (3) With substituted allyltrifluoroborates (e.g., crotyl-BF3K) mixtures of site isomers are generated as a result of transmetalation followed by Rh-(allyl) complex equilibration, consequently disproving outer-sphere addition of the allyl nucleophile to Rh(III)-(η3-allyl). (4) Stereochemical analysis of a cyclohexadiene allyl addition product supports a syn Rh(III)-hydride addition. (5) A Hammett plot shows a negative slope. Finally, utility is highlighted by a iodocyclization and cross metathesis.",

keywords = "alkene, allyltrifluoroborates, carbodicarbene ligands, hydroallylation, rhodium catalysis",

author = "Marcum, {Justin S.} and Cervarich, {Tia N.} and Manan, {Rajith S.} and Roberts, {Courtney C.} and Meek, {Simon J.}",

note = "Funding Information: Financial support was provided by the NSF (CHE-1665125) and the University of North Carolina at Chapel Hill. J.S.M. is grateful for a Burroughs-Welcome fellowship from the UNC Chemistry Department. We thank the University of North Carolina's Department of Chemistry Mass Spectrometry Core Laboratory for their assistance with mass spectrometry analysis. This material is based upon work supported by the National Science Foundation under Grant No. (CHE1726291). Funding Information: Financial support was provided by the NSF (CHE-1665125) and the University of North Carolina at Chapel Hill. J.S.M. is grateful for a Burroughs-Welcome fellowship from the UNC Chemistry Department. We thank the University of North Carolina{\textquoteright}s Department of Chemistry Mass Spectrometry Core Laboratory for their assistance with mass spectrometry analysis. This material is based upon work supported by the National Science Foundation under Grant No. (CHE1726291). Publisher Copyright: {\textcopyright} 2019 American Chemical Society.",

year = "2019",

month = may,

day = "22",

doi = "10.1021/acscatal.9b01579",

language = "English (US)",

volume = "9",

pages = "5881--5889",

journal = "ACS Catalysis",

issn = "2155-5435",

publisher = "American Chemical Society",

number = "7",

}

TY - JOUR

T1 - (CDC)-Rhodium-catalyzed hydroallylation of vinylarenes and 1,3-dienes with allyltrifluoroborates

AU - Marcum, Justin S.

AU - Cervarich, Tia N.

AU - Manan, Rajith S.

AU - Roberts, Courtney C.

AU - Meek, Simon J.

N1 - Funding Information: Financial support was provided by the NSF (CHE-1665125) and the University of North Carolina at Chapel Hill. J.S.M. is grateful for a Burroughs-Welcome fellowship from the UNC Chemistry Department. We thank the University of North Carolina's Department of Chemistry Mass Spectrometry Core Laboratory for their assistance with mass spectrometry analysis. This material is based upon work supported by the National Science Foundation under Grant No. (CHE1726291). Funding Information: Financial support was provided by the NSF (CHE-1665125) and the University of North Carolina at Chapel Hill. J.S.M. is grateful for a Burroughs-Welcome fellowship from the UNC Chemistry Department. We thank the University of North Carolina’s Department of Chemistry Mass Spectrometry Core Laboratory for their assistance with mass spectrometry analysis. This material is based upon work supported by the National Science Foundation under Grant No. (CHE1726291). Publisher Copyright: © 2019 American Chemical Society.

PY - 2019/5/22

Y1 - 2019/5/22

N2 - Catalytic site-selective hydroallylation of vinyl arenes and 1,3-dienes is reported. Transformations are promoted by a readily accessible bidentate carbodicarbene-rhodium complex and involve commercially available allyltrifluoroborates and an alcohol. The reaction is applicable to vinyl arenes and aryl-or alkyl-substituted 1,3-dienes (30 examples). Allyl addition products are generated in 40-78% yield and in up to >98:2 site selectivity. Reaction outcomes are consistent with the intermediacy of a Rh(III)-hydride generated by protonation of Rh(I) by an acid. A number of key mechanistic details of the reaction are presented: (1) Deuterium scrambling into the product and starting alkene indicates reversible Rh(III)-H migratory insertion. (2) A large primary kinetic isotope effect is observed. (3) With substituted allyltrifluoroborates (e.g., crotyl-BF3K) mixtures of site isomers are generated as a result of transmetalation followed by Rh-(allyl) complex equilibration, consequently disproving outer-sphere addition of the allyl nucleophile to Rh(III)-(η3-allyl). (4) Stereochemical analysis of a cyclohexadiene allyl addition product supports a syn Rh(III)-hydride addition. (5) A Hammett plot shows a negative slope. Finally, utility is highlighted by a iodocyclization and cross metathesis.

AB - Catalytic site-selective hydroallylation of vinyl arenes and 1,3-dienes is reported. Transformations are promoted by a readily accessible bidentate carbodicarbene-rhodium complex and involve commercially available allyltrifluoroborates and an alcohol. The reaction is applicable to vinyl arenes and aryl-or alkyl-substituted 1,3-dienes (30 examples). Allyl addition products are generated in 40-78% yield and in up to >98:2 site selectivity. Reaction outcomes are consistent with the intermediacy of a Rh(III)-hydride generated by protonation of Rh(I) by an acid. A number of key mechanistic details of the reaction are presented: (1) Deuterium scrambling into the product and starting alkene indicates reversible Rh(III)-H migratory insertion. (2) A large primary kinetic isotope effect is observed. (3) With substituted allyltrifluoroborates (e.g., crotyl-BF3K) mixtures of site isomers are generated as a result of transmetalation followed by Rh-(allyl) complex equilibration, consequently disproving outer-sphere addition of the allyl nucleophile to Rh(III)-(η3-allyl). (4) Stereochemical analysis of a cyclohexadiene allyl addition product supports a syn Rh(III)-hydride addition. (5) A Hammett plot shows a negative slope. Finally, utility is highlighted by a iodocyclization and cross metathesis.

KW - alkene

KW - allyltrifluoroborates

KW - carbodicarbene ligands

KW - hydroallylation

KW - rhodium catalysis

UR - http://www.scopus.com/inward/record.url?scp=85070584808&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85070584808&partnerID=8YFLogxK

U2 - 10.1021/acscatal.9b01579

DO - 10.1021/acscatal.9b01579

M3 - Article

AN - SCOPUS:85070584808

SN - 2155-5435

VL - 9

SP - 5881

EP - 5889

JO - ACS Catalysis

JF - ACS Catalysis

IS - 7

ER -

(CDC)-Rhodium-catalyzed hydroallylation of vinylarenes and 1,3-dienes with allyltrifluoroborates

Abstract

Bibliographical note

Keywords

Access

OpenUrl availability

Other files and links

Fingerprint

Cite this