Resolving a Reactive Organometallic Intermediate from Dynamic Directing Group Systems by Selective C−H Activation
作者:Fredrik Schaufelberger、Brian J. J. Timmer、Olof Ramström
DOI:10.1002/chem.201705273
日期:2018.1.2
from systems of potential precursors is a challenging endeavor. Herein, a new strategy applying dynamic chemistry to the identification of catalyst precursors from C-H activation of imines is proposed and evaluated. Using hydroacylation of imines as a model reaction, the selection of an organometallic reactive intermediate from a dynamic imine system, involving many potential directing group/metal
The clay montmorillonite K10 is an efficient acidic solid that can act as a reusable co-catalyst in the condensation reaction of aldehydes and amines to provide the imine intermediate which is then transformed into the ketone through the hydroiminoacylation reaction, in the presence of rhodium complexes.
A Rh(I)-catalyzed ketone Suzuki–Miyaura couplingreaction of benzylacetone with arylboronic acid is developed. Selective C(O)–C bond activation, which employs aminopyridine as a temporary directing group and ethyl vinyl ketone as a hydride acceptor, occurs on the alkyl chain containing a β-position hydrogen. A series of acetophenone products were obtained in yields up to 75%.
1,4-Dicarbonyl compounds can be prepared using a Rh(I) mediated hydroacylation reaction between (2-aminopicolyl)imines and acrylate esters followed by acid hydrolysis.