A Quintuple [6]Helicene with a Corannulene Core as a C5-Symmetric Propeller-Shaped π-System

Kenta Kato; Yasutomo Segawa; Lawrence T. Scott; Kenichiro Itami

doi:10.1002/anie.201711985

A Quintuple [6]Helicene with a Corannulene Core as a C₅-Symmetric Propeller-Shaped π-System

Kenta Kato, Yasutomo Segawa, Lawrence T. Scott, Kenichiro Itami

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

43 Citations (Scopus)

Abstract

The synthesis and structural analysis of a quintuple [6]helicene with a corannulene core is reported. The compound was synthesized from corannulene in three steps including a five-fold intramolecular direct arylation. X-ray crystallographic analysis revealed a C₅-symmetric propeller-shaped structure and one-dimensional alignment in the solid state. The enantiomers of the quintuple [6]helicene were successfully separated by HPLC, and the chirality of the two fractions was identified by CD spectroscopy. A kinetic study yielded a racemization barrier of 34.2 kcal mol⁻¹, which is slightly lower than that of pristine [6]helicene. DFT calculations indicate a rapid bowl-to-bowl inversion of the corannulene moiety and a step-by-step chiral inversion pathway for the five [6]helicene moieties.

Original language	English
Pages (from-to)	1337-1341
Number of pages	5
Journal	Angewandte Chemie - International Edition
Volume	57
Issue number	5
DOIs	https://doi.org/10.1002/anie.201711985
Publication status	Published - 2018 Jan 26
Externally published	Yes

Keywords

arenes
corannulenes
helicenes
polycycles

ASJC Scopus subject areas

Catalysis
Chemistry(all)

Access to Document

10.1002/anie.201711985

Fingerprint Dive into the research topics of 'A Quintuple [6]Helicene with a Corannulene Core as a C<sub>5</sub>-Symmetric Propeller-Shaped π-System'. Together they form a unique fingerprint.

Cite this

@article{e4bccbf2580249828c39a188b146e2d1,

title = "A Quintuple [6]Helicene with a Corannulene Core as a C5-Symmetric Propeller-Shaped π-System",

abstract = "The synthesis and structural analysis of a quintuple [6]helicene with a corannulene core is reported. The compound was synthesized from corannulene in three steps including a five-fold intramolecular direct arylation. X-ray crystallographic analysis revealed a C5-symmetric propeller-shaped structure and one-dimensional alignment in the solid state. The enantiomers of the quintuple [6]helicene were successfully separated by HPLC, and the chirality of the two fractions was identified by CD spectroscopy. A kinetic study yielded a racemization barrier of 34.2 kcal mol−1, which is slightly lower than that of pristine [6]helicene. DFT calculations indicate a rapid bowl-to-bowl inversion of the corannulene moiety and a step-by-step chiral inversion pathway for the five [6]helicene moieties.",

keywords = "arenes, corannulenes, helicenes, polycycles",

author = "Kenta Kato and Yasutomo Segawa and Scott, {Lawrence T.} and Kenichiro Itami",

note = "Funding Information: This work was supported by the ERATO program from JST (JPMJER1302 to K.I.), the Funding Program for KAKENHI from MEXT (JP16K05771 to Y.S.), a grant-in-aid for Scientific Research on Innovative Areas “p-Figuration” from JSPS (JP17H05149 to Y.S.), the Noguchi Institute (to Y.S.), and the US National Science Foundation (CHE-1149096 to L.T.S.). K.K. thanks IGER Program in Green Natural Sciences, Nagoya University and a JSPS fellowship for young scientists. Calculations were performed using the resources of the Research Center for Computational Science, Okazaki, Japan. ITbM is supported by the World Premier International Research Center Initiative (WPI), Japan.",

year = "2018",

month = jan,

day = "26",

doi = "10.1002/anie.201711985",

language = "English",

volume = "57",

pages = "1337--1341",

journal = "Angewandte Chemie - International Edition",

issn = "1433-7851",

publisher = "John Wiley and Sons Ltd",

number = "5",

}

TY - JOUR

T1 - A Quintuple [6]Helicene with a Corannulene Core as a C5-Symmetric Propeller-Shaped π-System

AU - Kato, Kenta

AU - Segawa, Yasutomo

AU - Scott, Lawrence T.

AU - Itami, Kenichiro

N1 - Funding Information: This work was supported by the ERATO program from JST (JPMJER1302 to K.I.), the Funding Program for KAKENHI from MEXT (JP16K05771 to Y.S.), a grant-in-aid for Scientific Research on Innovative Areas “p-Figuration” from JSPS (JP17H05149 to Y.S.), the Noguchi Institute (to Y.S.), and the US National Science Foundation (CHE-1149096 to L.T.S.). K.K. thanks IGER Program in Green Natural Sciences, Nagoya University and a JSPS fellowship for young scientists. Calculations were performed using the resources of the Research Center for Computational Science, Okazaki, Japan. ITbM is supported by the World Premier International Research Center Initiative (WPI), Japan.

PY - 2018/1/26

Y1 - 2018/1/26

N2 - The synthesis and structural analysis of a quintuple [6]helicene with a corannulene core is reported. The compound was synthesized from corannulene in three steps including a five-fold intramolecular direct arylation. X-ray crystallographic analysis revealed a C5-symmetric propeller-shaped structure and one-dimensional alignment in the solid state. The enantiomers of the quintuple [6]helicene were successfully separated by HPLC, and the chirality of the two fractions was identified by CD spectroscopy. A kinetic study yielded a racemization barrier of 34.2 kcal mol−1, which is slightly lower than that of pristine [6]helicene. DFT calculations indicate a rapid bowl-to-bowl inversion of the corannulene moiety and a step-by-step chiral inversion pathway for the five [6]helicene moieties.

AB - The synthesis and structural analysis of a quintuple [6]helicene with a corannulene core is reported. The compound was synthesized from corannulene in three steps including a five-fold intramolecular direct arylation. X-ray crystallographic analysis revealed a C5-symmetric propeller-shaped structure and one-dimensional alignment in the solid state. The enantiomers of the quintuple [6]helicene were successfully separated by HPLC, and the chirality of the two fractions was identified by CD spectroscopy. A kinetic study yielded a racemization barrier of 34.2 kcal mol−1, which is slightly lower than that of pristine [6]helicene. DFT calculations indicate a rapid bowl-to-bowl inversion of the corannulene moiety and a step-by-step chiral inversion pathway for the five [6]helicene moieties.

KW - arenes

KW - corannulenes

KW - helicenes

KW - polycycles

UR - http://www.scopus.com/inward/record.url?scp=85040172966&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85040172966&partnerID=8YFLogxK

U2 - 10.1002/anie.201711985

DO - 10.1002/anie.201711985

M3 - Article

C2 - 29280250

AN - SCOPUS:85040172966

VL - 57

SP - 1337

EP - 1341

JO - Angewandte Chemie - International Edition

JF - Angewandte Chemie - International Edition

SN - 1433-7851

IS - 5

ER -