Please use this identifier to cite or link to this item:
Title: Bisimino-functionalized dibenzo[a,c]acridines as highly conjugated pincer frameworks for palladium(II): synthesis, characterization and catalytic performance in Heck coupling
Authors: Mahmood, Qaiser
Yue, Erlin
Zhang, Wenjuan
Solan, Gregory A.
Liang, Tongling
Sun, Wen-Hua
First Published: 27-Sep-2016
Publisher: Royal Society of Chemistry
Citation: Organic Chemistry Frontiers, 2016, 3 (12), pp. 1668-1679
Abstract: A new pair of highly conjugated ligands, 10-[1-(arylimino)ethyl]-14-[(arylimino)methyl]dibenzo[a,c]acridine (aryl = 2,6-Me₂Ph L1, 2,6-Et₂Ph L2) incorporating both aldimine and ketimine units, have been prepared by a straightforward sequence of organic transformations from phenanthrene-9,10-dione. Cyclopalladation occurs readily at ambient temperature on treating L1 or L2 with PdCl₂(NCCH₃)₂ in aprotic solvents to afford exclusively (NketimineNC)Pd(II) chloride pincer complexes Pd1 or Pd2, respectively. By contrast in methanol, Pd1 or Pd2 are isolated as the minor product with aldehyde-containing Pd3 or Pd4 as the major one, the result of hydrolysis of the pendant aldimine units in Pd1 and Pd2, respectively. All the ligands and palladium complexes have been characterized by FT-IR, ¹H and ¹³C NMR spectroscopy, mass spectrometry and elemental analysis; the molecular structures for L1, Pd1, Pd2, Pd3 and Pd4 are also reported. Using low catalyst loadings (0.0005–0.002 mol%) and elevated temperatures (140–200 °C), Pd1–Pd4 are able to efficiently mediate the coupling of haloarenes with vinyl-containing substrates with turnover numbers as high as 174000; the effects of steric/electronic variation within the substrate and NNC-pincer complex on catalyst performance are examined.
DOI Link: 10.1039/c6qo00469e
ISSN: 2052-4110
eISSN: 2052-4129
Version: Post-print
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © 2016, Royal Society of Chemistry. Deposited with reference to the publisher’s open access archiving policy.
Description: The file associated with this record is under a 12 month embargo from publication in accordance with the publisher's self-archiving policy. The full text may be available through the publisher links provided above.
Appears in Collections:Published Articles, Dept. of Chemistry

Files in This Item:
File Description SizeFormat 
160911-manuscript_2REVISED_GAS.pdfPost-review (final submitted author manuscript)541.41 kBAdobe PDFView/Open

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.