Open AccessInherent Selectivity of Pd C–H Activation from Different Metal Oxidation States
Author(s) -
Peter Amadeo,
Bangaru Bhaskararao,
YunFang Yang,
Marisa C. Kozlowski
Publication year - 2021
Publication title -
organometallics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.231
H-Index - 172
eISSN - 1520-6041
pISSN - 0276-7333
DOI - 10.1021/acs.organomet.1c00011
Subject(s) - chemistry , palladium , steric effects , selectivity , ligand (biochemistry) , oxidation state , toluene , catalysis , metal , medicinal chemistry , stereochemistry , photochemistry , organic chemistry , receptor , biochemistry
In investigating potential control factors that would permit a palladium-catalyzed benzylic vs arene C-H activation as previously reported by our group, it was discovered that the oxidation state of the homogenous palladium species influences the selectivity of C-H activation. DFT calculations show that Pd 0 and Pd I preferentially activate the sp 3 C-H bond in toluene, whereas Pd II and Pd III preferentially activate the sp 2 C-H bond. This selectivity appears to originate from the steric environment created by the ligand framework on the palladium. As the palladium oxidation state increases, the number of ligand sites increases, which decreases the energetic favorability for activation of the weaker, yet more hindered sp 3 C-H bond.