The synthesis of 12-membered macrocycles containing a C1–C8 alkene unit via ring-closing metathesis
摘要:
Model cross and ring-closing metathesis strategies toward the C1-C8-linear carbon skeleton are presented. The introduction of a four-atom tether enables the formation of 12-membered rings in good-to-excellent yields and stereoselectivity. Furthermore, the study revealed that the cross-metathesis approach and the formation of medium ring sizes via ring-closing metathesis are much less favorable. (C) 2012 Elsevier Ltd. All rights reserved.
Model cross and ring-closing metathesis strategies toward the C1-C8-linear carbon skeleton are presented. The introduction of a four-atom tether enables the formation of 12-membered rings in good-to-excellent yields and stereoselectivity. Furthermore, the study revealed that the cross-metathesis approach and the formation of medium ring sizes via ring-closing metathesis are much less favorable. (C) 2012 Elsevier Ltd. All rights reserved.
Single-Molecule Activation and Quantification of Mechanically Triggered Palladium–Carbene Bond Dissociation
作者:Anton O. Razgoniaev、Logan M. Glasstetter、Tatiana B. Kouznetsova、Kacey C. Hall、Matias Horst、Stephen L. Craig、Katherine J. Franz
DOI:10.1021/jacs.0c13219
日期:2021.2.3
ligand dissociation from a pincer NHC-pyridine-NHC Pd(II) complex. The force-coupled rate constant for ligand dissociation reaches 50 s-1 at forces of approximately 930 pN. Experimental and computational observations support a dissociative, rather than associative, mechanism of ligand displacement, with rate-limiting scission of the Pd-NHC bond followed by rapid dissociation of the pyridine moiety