1603-55-0Relevant articles and documents
Pd- η3-C6H9 complexes of the Trost modular ligand: High nuclearity columnar aggregation controlled by concentration, solvent and counterion
Racys, Daugirdas Tomas,Eastoe, Julian,Norrby, Per-Ola,Grillo, Isabelle,Rogers, Sarah E.,Lloyd-Jones, Guy C.
, p. 5793 - 5801 (2015/09/28)
Under optimised conditions, the Trost modular ligand (TML) series induces high levels of asymmetric induction in an extraordinarily wide range of reactions involving palladium π-allyl intermediates. Prior mechanistic investigations into reactions involving Pd-η3-C6H9 intermediates have focussed on the monomeric 13-membered ring formed via P,P-chelation of the ligand to Pd. However, it is also recognised that ring-opening oligomerisation provides a pool of high nuclearity Pd-η3-C6H9 species that, by affording a low level, or even the opposite sense, of asymmetric induction relative to the mononuclear species, are responsible for a reduction in selectivity under non-optimised conditions. Herein we describe an investigation by NMR spectroscopy, molecular mechanics, molecular dynamics, and small-angle neutron scattering (SANS), of a Pd-η3-C6H9 cation bearing the 1,2-diaminocyclohexane TML ligand (2). Using both nondeuterated and perdeuterated (D47) isotopologues of the resulting complexes ([1]+), we show that a two-stage oligomerisation-aggregation process forms self assembled cylindrical aggregates of very high nuclearity (up to 56 Pd centres). We also investigate how concentration, solvent and counter-anion all modulate the extent of oligomerisation.
Protium-deuterium exchange of cyclic and acyclic alkanens in dilute acid medium at elevated temperatures
Werstiuk, Nick Henry,Timmins, George
, p. 530 - 533 (2007/10/02)
A modification of the high temperature - dilute acid (HTDA) method for deuterium labelling of aromatic compounds has been applied to the H-D exchange of a number of cyclic and acyclic alkenes.Cyclopentene, cyclohexene, cyclododecene, and tetramethylethylene have been completely exchanged in excellent yield. 1-Methylcyclopentene and 1-methylcyclohexene have also been perdeuterated and cycloheptene and cyclooctene partially labelled but require spinning band distillation or preparative glpc for separation from rearrangement products.A variety of C5-C8 acyclic alkeneshave also been treated under HTDA conditions.