efficient approach was developed for the α-alkylation of various nitriles with carbonyl compounds using ruthenium-amido complex catalyst 1. The C-C bond was formed through aldol reaction followed by hydrogenation with triethylamine-formic acid (TEAF) and 1. Moderate to high yields were obtained, and a variety of functional groups were tolerated, including nitro and chloro groups, and a furan ring. ruthenium-amido
Novel triethylamine mediated thermal reactions of 3-aryl-2-cyanoprop-2-enoic acid derivatives—demethylation, reduction and vinylogation
作者:Attimogae Shivamurthy Harisha、Suresh Parameshwar Nayak、Kuppuswamy Nagarajan、Tayur Narasingarow Guru Row、Amar A. Hosamani
DOI:10.1016/j.tetlet.2015.01.148
日期:2015.3
3-Aryl-2-propenoic acid derivatives undergo interesting reactions with hot triethylamine. Substrates like 6 having a methoxyl with a nitro in the ortho and cyanoacrylic derivatives in the para positions give O-demethylated products, for example, entacapone 7. On the other hand compounds like 16 having the NO2 in the para and cyanoacrylic in the ortho position undergo reduction and vinylogation. The latter phenomenon is observed in the absence of the NO2 group also. (C) 2015 Elsevier Ltd. All rights reserved.
Overturning Established Chemoselectivities: Selective Reduction of Arenes over Malonates and Cyanoacetates by Photoactivated Organic Electron Donors
作者:Eswararao Doni、Bhaskar Mondal、Steven O’Sullivan、Tell Tuttle、John A. Murphy
DOI:10.1021/ja4050168
日期:2013.7.31
The prevalence of metal-based reducing reagents, including metals, metal complexes, and metal salts, has produced an empirical order of reactivity that governs our approach to chemical synthesis. However, this reactivity may be influenced by stabilization of transition states, intermediates, and products through substrate metal bonding. This article reports that in the absence of such stabilizing interactions, established chemoselectivities can be overthrown. Thus, photoactivation of the recently developed neutral organic superelectron donor 5 selectively reduces alkyl-substituted benzene rings in the presence of activated esters and nitriles, in direct contrast to metal-based reductions, opening a new perspective on reactivity. The altered outcomes arising from the organic electron donors are attributed to selective interactions between the neutral organic donors and the arene rings of the substrates.