Selective Heck reaction of electron-rich aryl bromides with cyclic alkenones
作者:Tarak Nath Gowala、Jagadish Pabba
DOI:10.1016/j.tetlet.2015.02.045
日期:2015.4
A simple and efficient protocol for the Heck reaction of cyclic alkenones with electron-rich aryl bromides has been developed. A ligand combination of X-Phos and tri-tert-butylphosphonium hydrogen tetrafluorborate in the presence of Pd(PPh3)(2)Cl-2 and Na2CO3 in DMSO was found to be efficient and selective for electron-rich aryl bromides with high substrate scope for cyclic alkenones. (C) 2015 Elsevier Ltd. All rights reserved.
Isopropylmagnesium chloride-promoted unilateral addition of Grignard reagents to β-diketones: one-pot syntheses of β-tertiary hydroxyl ketones or 3-substituted cyclic-2-enones
作者:Rui Yuan、Dan Zhao、Li-Yuan Zhang、Xiang Pan、Yan Yang、Pei Wang、Hong-Feng Li、Chao-Shan Da
DOI:10.1039/c5ob02072g
日期:——
unilateral additions of Grignardreagents to acyclic or cyclic β-diketones were effectively promoted by sub-stoichiometric amounts of i-PrMgCl to afford β-tertiary hydroxyl ketones or 3-substituted cyclic-2-enones, respectively. Also, the addition of Grignardreagents to acyclic β-diketones followed by a reaction with cyclic β-diketones in a one-pot process was put forward. The reaction mechanism was discussed
Enantioselective Synthesis of Boron-Substituted Quaternary Carbon Stereogenic Centers through NHC-Catalyzed Conjugate Additions of (Pinacolato)boron Units to Enones
作者:Suttipol Radomkit、Amir H. Hoveyda
DOI:10.1002/anie.201309982
日期:2014.3.24
base catalyzed enantioselective boryl conjugate additions (BCAs) that generate products containing boron‐substituted quaternarycarbonstereogeniccenters are disclosed. Reactions are performed in the presence of 1.0–5.0 mol % of a readily accessible chiral accessible N‐heterocyclic carbene (NHC) and commercially available bis(pinacolato)diboron; cyclic or linear α,β‐unsaturated ketones can be used and