1352802-53-9Relevant academic research and scientific papers
1,2,3-triazolin-5-ylidenes: Synthesis of hetero-bis(carbene) Pd(II) complexes, determination of donor strengths, and catalysis
Yuan, Dan,Huynh, Han Vinh
, p. 405 - 412 (2012/04/23)
A series of hetero-bis(carbene) complexes trans-[PdBr2( iPr2-bimy)(trz)] 1-4 (iPr2-bimy = 1,3-diisopropylbenzimidazolin-2-ylidene; trz = 1,2,3-triazolin-5-ylidene) bearing the constant iPr2-bimy and varying mesoionic 1,2,3-triazolin-5-ylidenes with different N-substituents has been synthesized as complex probes. Their 13C NMR spectroscopic evaluation shows that mesoionic 1,2,3-triazolin-5-ylidenes are, in general, stronger donors than classical NHCs, while weaker than some nonclassical NHCs, such as pyrazolin-3-ylidenes and mesoionic imidazolin-4-ylidenes. More importantly and for the first time, this methodology proves useful in establishing substituent effects in the donating abilities of 1,2,3-triazolin-5-ylidenes on a finer level. In addition, the trifluoroacetato analogues [Pd(O2CCF 3)2(iPr2-bimy)(trz)] 5-7 have been synthesized through salt metathesis of 1, 2, and 4 with AgO2CCF 3. The catalytic activities of complexes 1, 2, and 4-7 were examined in the direct arylation of pentafluorobenzene. Complexes bearing less donating trz ligands perform better in this catalysis, and trifluoroacetato complexes outperformed their bromido analogues.
