Diazaphosphinyl radical-catalyzed deoxygenation of α-carboxy ketones: a new protocol for chemo-selective C–O bond scission <i>via</i> mechanism regulation
作者:Jingjing Zhang、Jin-Dong Yang、Jin-Pei Cheng
DOI:10.1039/d0sc03220d
日期:——
diazaphosphinane based on a mechanism switch strategy. This new reaction features high efficiency, low cost and good group-tolerance, and is also amenable to catalytic deprotection of desyl-protected carboxylic acids and amino acids. Mechanistic studies indicated an electron-transfer-initiated radical process, underlining two crucial steps: (1) the initiator azodiisobutyronitrile switches originally hydridic
Pd-catalyzed synthesis of α-aryl ketones through couplings of α-arylacetyl chlorides with triarylbismuths as multi-coupling nucleophiles
作者:Maddali L.N. Rao、Somnath Giri、Deepak N. Jadhav
DOI:10.1016/j.tetlet.2009.08.074
日期:2009.11
The cross-coupling reaction of alpha-arylacetyl chlorides with triarylbismuths was studied under Pd-catalyzed conditions. The reaction was found to be facile under the established protocol and furnished high yields of alpha-aryl ketones in short reaction times. This work also demonstrated a facile synthesis of various regio-isomeric mono-, di- and tri-substituted alpha-aryl ketones in high yields. Triarylbisrnuths were employed as sub-stoichiometric multi-coupling organometallic nucleophiles in this coupling protocol. (C) 2009 Elsevier Ltd. All rights reserved.
C–O σ-bonds in multifaceted benzoin derivatives can be effectively cleaved as acetates using catalytic amounts of [Ru(bpy)3]Cl2 as photoredox catalyst in combination with Hantzsch ester and triethylamine as a sacrificial electron donor. This mild and operationally simple method is applicable to a great variety of substrates. Homo- and cross-benzoins, which are easily accessed by NHC (N-heterocyclic