56296-23-2Relevant academic research and scientific papers
Photochemical Cleavage of Benzylic C-O Bond Facilitated by an Ortho or Meta Amino Group
Ding, Xiong,Wang, Pengfei
, p. 7309 - 7316 (2017)
The excited state meta effect, also known as the meta-ortho effect, results from selective electron transmission from an electron-donating group to the meta and ortho sites on an aromatic ring in its first excited singlet state. This effect facilitates photochemical cleavage of benzylic C-O or C-N bond to release the corresponding alcohol, carboxylic acid, or amine when an electron-donating amino group is at the meta position, as demonstrated in our recent work of using a 3-diethylaminobenzyl (DEABn) group as an effective photolabile protecting group (PPG). Herein, we demonstrate that an ortho amino group can also facilitate benzylic C-O bond cleavage to release an alcohol or carboxylic acid. However, an amino group at the meta position results in a PPG with better overall chemical and photochemical properties.
Highly active and recyclable heterogeneous iridium pincer catalysts for transfer dehydrogenation of alkanes
Huang, Zheng,Brookhart, Maurice,Goldman, Alan S.,Kundu, Sabuj,Ray, Amlan,Scott, Susannah L.,Vicente, Brian C.
experimental part, p. 188 - 206 (2009/10/02)
Pincer-ligated iridium complexes have proven to be highly effective catalysts for the dehydrogenation and transfer-dehydrogenation of alkanes. Immobilization onto a solid support offers significant potential advantages in the application of such catalysts particularly with respect to catalyst separation and recycling. We describe three approaches toward such immobilization: (i) covalent attachment to a Merrifield resin, (ii) covalent bonding to silica via a pendant alkoxysilane group, and (iii) adsorption on γ-alumina (γ-Al2O3), through basic functional groups on the para-position of the pincer ligand. The simplest of these approaches, adsorption on γ-Al2O3, is also found to be the most effective, yielding catalysts that are robust, recyclable, and comparable to or even more active than the corresponding species in solution. Spectroscopic evidence (NMR, IR) and studies of catalytic activity support the hypothesis that binding occurs at the para-substituent and that this has only a relatively subtle and indirect influence on catalytic behavior.
