Rational design of ligand precursors to prepare abnormal (mesoionic) and normal carbene complexes and zwitterionic CX-type palladacycles (X = C, N)

Shih Ji Chen, Yuan Deng Lin, Yen Hsin Chiang, Hon Man Lee

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

The preparation of a series of ligand precursors that feature imidazo[1,2-a]pyridine and amido functional groups is reported. The reactions between the new ligand precursors, pyridine, and palladium acetate in DMF afforded monodentate PdII abnormal (mesoionic) carbene complexes. An isomeric PdII normal carbene complex with a formally identical steric environment to that of the abnormal carbene counterpart was also prepared. The isomeric pairs were characterized by X-ray structural studies. Under different complexation conditions, in which PdCl2 was employed as metal precursor, a zwitterionic CC-type palladacycle formed by the C-H activation at the ortho-N-phenyl and methylene carbon atoms was obtained. The use of a similar ligand precursor with an NH instead of an NMe group produced a zwitterionic palladalactam complex. In contrast to the previous work in the literature, owing to the rigidity of the fused heterocyclic ring, the palladalactam complex did not undergo intramolecular proton transfer through the coordinated N atom. Overall, we demonstrated that proper modification of the structures of ligand precursors and complexation conditions allowed us to obtain a full range of intriguing PdII complexes including normal and abnormal carbene complexes, and zwitterionic palladalactam and CC-type palladacycles by means of A-H bond (A = N, C) activations. Rational modification of the structures of ligand precursors and complexation conditions to obtain a full range of intriguing PdII complexes including abnormal (mesoionic) and normal carbene complexes, and zwitterionic palladalactam and CC-type palladacycles by means of A-H bond (A = N, C) activations is described.

Original languageEnglish
Pages (from-to)1492-1501
Number of pages10
JournalEuropean Journal of Inorganic Chemistry
Issue number9
DOIs
Publication statusPublished - 2014 Jan 1

Fingerprint

Ligands
Complexation
Chemical activation
Atoms
Proton transfer
Palladium
Rigidity
Functional groups
Acetates
Carbon
Metals
carbene
X rays

All Science Journal Classification (ASJC) codes

  • Inorganic Chemistry

Cite this

@article{a41e0980430446c084a8c50212c07f29,
title = "Rational design of ligand precursors to prepare abnormal (mesoionic) and normal carbene complexes and zwitterionic CX-type palladacycles (X = C, N)",
abstract = "The preparation of a series of ligand precursors that feature imidazo[1,2-a]pyridine and amido functional groups is reported. The reactions between the new ligand precursors, pyridine, and palladium acetate in DMF afforded monodentate PdII abnormal (mesoionic) carbene complexes. An isomeric PdII normal carbene complex with a formally identical steric environment to that of the abnormal carbene counterpart was also prepared. The isomeric pairs were characterized by X-ray structural studies. Under different complexation conditions, in which PdCl2 was employed as metal precursor, a zwitterionic CC-type palladacycle formed by the C-H activation at the ortho-N-phenyl and methylene carbon atoms was obtained. The use of a similar ligand precursor with an NH instead of an NMe group produced a zwitterionic palladalactam complex. In contrast to the previous work in the literature, owing to the rigidity of the fused heterocyclic ring, the palladalactam complex did not undergo intramolecular proton transfer through the coordinated N atom. Overall, we demonstrated that proper modification of the structures of ligand precursors and complexation conditions allowed us to obtain a full range of intriguing PdII complexes including normal and abnormal carbene complexes, and zwitterionic palladalactam and CC-type palladacycles by means of A-H bond (A = N, C) activations. Rational modification of the structures of ligand precursors and complexation conditions to obtain a full range of intriguing PdII complexes including abnormal (mesoionic) and normal carbene complexes, and zwitterionic palladalactam and CC-type palladacycles by means of A-H bond (A = N, C) activations is described.",
author = "Chen, {Shih Ji} and Lin, {Yuan Deng} and Chiang, {Yen Hsin} and Lee, {Hon Man}",
year = "2014",
month = "1",
day = "1",
doi = "10.1002/ejic.201301465",
language = "English",
pages = "1492--1501",
journal = "Chemische Berichte",
issn = "0009-2940",
publisher = "Wiley-VCH Verlag",
number = "9",

}

Rational design of ligand precursors to prepare abnormal (mesoionic) and normal carbene complexes and zwitterionic CX-type palladacycles (X = C, N). / Chen, Shih Ji; Lin, Yuan Deng; Chiang, Yen Hsin; Lee, Hon Man.

In: European Journal of Inorganic Chemistry, No. 9, 01.01.2014, p. 1492-1501.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Rational design of ligand precursors to prepare abnormal (mesoionic) and normal carbene complexes and zwitterionic CX-type palladacycles (X = C, N)

AU - Chen, Shih Ji

AU - Lin, Yuan Deng

AU - Chiang, Yen Hsin

AU - Lee, Hon Man

PY - 2014/1/1

Y1 - 2014/1/1

N2 - The preparation of a series of ligand precursors that feature imidazo[1,2-a]pyridine and amido functional groups is reported. The reactions between the new ligand precursors, pyridine, and palladium acetate in DMF afforded monodentate PdII abnormal (mesoionic) carbene complexes. An isomeric PdII normal carbene complex with a formally identical steric environment to that of the abnormal carbene counterpart was also prepared. The isomeric pairs were characterized by X-ray structural studies. Under different complexation conditions, in which PdCl2 was employed as metal precursor, a zwitterionic CC-type palladacycle formed by the C-H activation at the ortho-N-phenyl and methylene carbon atoms was obtained. The use of a similar ligand precursor with an NH instead of an NMe group produced a zwitterionic palladalactam complex. In contrast to the previous work in the literature, owing to the rigidity of the fused heterocyclic ring, the palladalactam complex did not undergo intramolecular proton transfer through the coordinated N atom. Overall, we demonstrated that proper modification of the structures of ligand precursors and complexation conditions allowed us to obtain a full range of intriguing PdII complexes including normal and abnormal carbene complexes, and zwitterionic palladalactam and CC-type palladacycles by means of A-H bond (A = N, C) activations. Rational modification of the structures of ligand precursors and complexation conditions to obtain a full range of intriguing PdII complexes including abnormal (mesoionic) and normal carbene complexes, and zwitterionic palladalactam and CC-type palladacycles by means of A-H bond (A = N, C) activations is described.

AB - The preparation of a series of ligand precursors that feature imidazo[1,2-a]pyridine and amido functional groups is reported. The reactions between the new ligand precursors, pyridine, and palladium acetate in DMF afforded monodentate PdII abnormal (mesoionic) carbene complexes. An isomeric PdII normal carbene complex with a formally identical steric environment to that of the abnormal carbene counterpart was also prepared. The isomeric pairs were characterized by X-ray structural studies. Under different complexation conditions, in which PdCl2 was employed as metal precursor, a zwitterionic CC-type palladacycle formed by the C-H activation at the ortho-N-phenyl and methylene carbon atoms was obtained. The use of a similar ligand precursor with an NH instead of an NMe group produced a zwitterionic palladalactam complex. In contrast to the previous work in the literature, owing to the rigidity of the fused heterocyclic ring, the palladalactam complex did not undergo intramolecular proton transfer through the coordinated N atom. Overall, we demonstrated that proper modification of the structures of ligand precursors and complexation conditions allowed us to obtain a full range of intriguing PdII complexes including normal and abnormal carbene complexes, and zwitterionic palladalactam and CC-type palladacycles by means of A-H bond (A = N, C) activations. Rational modification of the structures of ligand precursors and complexation conditions to obtain a full range of intriguing PdII complexes including abnormal (mesoionic) and normal carbene complexes, and zwitterionic palladalactam and CC-type palladacycles by means of A-H bond (A = N, C) activations is described.

UR - http://www.scopus.com/inward/record.url?scp=84897871438&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84897871438&partnerID=8YFLogxK

U2 - 10.1002/ejic.201301465

DO - 10.1002/ejic.201301465

M3 - Article

AN - SCOPUS:84897871438

SP - 1492

EP - 1501

JO - Chemische Berichte

JF - Chemische Berichte

SN - 0009-2940

IS - 9

ER -