Rh<sup>III</sup>-Catalyzed Regioselective Preparation of 3-Hetero-Substituted Isocoumarins from Aryl Carboxylic Acids and Alkynes
作者:Lijuan Song、Jing Xiao、Wanrong Dong、Zhihong Peng、Delie An
DOI:10.1002/ejoc.201601330
日期:2017.1.10
An oxygen-mediated annulation reaction has been reported herein. Various 3-hetero-substituted isocoumarins were successfully prepared with high efficiency (yields up to 88 %) and good functional-group tolerance (35 examples) in the presence of a rhodium catalyst. A plausible mechanism has also been proposed that shows the high regioselectivity mostly likely originates from the electron-density difference
Copper-Catalyzed C-P Coupling through Decarboxylation
作者:Jie Hu、Ning Zhao、Bin Yang、Ge Wang、Li-Na Guo、Yong-Min Liang、Shang-Dong Yang
DOI:10.1002/chem.201003561
日期:2011.5.9
developed by copper‐catalyzed decarboxylative coupling of alkenyl, alkynyl carboxylic acids, and N‐benzylproline, respectively, with R2P(O)H (see scheme). All classes of products are important precursors for preparation of biologically active molecules and various phosphorus ligands. This finding represents the first example of copper‐catalyzed decarboxylative coupling to construct CP bonds.
A simple and mild methodology for the directsynthesis of alkynylphosphonates is presented. The reaction of a variety of terminalalkynes with dialkyl phosphites in the presence Cu2O (14 mol %) led to the formation of the corresponding alkynylphosphonates in good to excellent yields. Reactions are performed under air, in acetonitrile as solvent, and in the absence of base or ligand additives. This
Aerobic oxidative alkynylation of H-phosphonates and amides: an efficient route for the synthesis of alkynylphosphonates and ynamides using a recyclable Cu–MnO catalyst
作者:Harshvardhan Singh、Tapan Sahoo、Chiranjit Sen、Sunil M. Galani、Subhash Chandra Ghosh
DOI:10.1039/c9cy00275h
日期:——
and efficient route for the synthesis of alkynylphosphonates and ynamides by aerobic oxidative alkynylation of H-phosphonates and amides with both aliphatic and aromatic alkynes using our synthesized recyclable heterogeneous Cu–MnO catalyst has been developed. The phosphorylation was carried out under base- and ligand-free conditions, and in the presence of air as the sole oxidant. The reaction is compatible
Base-Induced One-Pot Preparation of N- or P-Substituted Alkynes
作者:Yang Zhang、Yanqin Zhang、Jing Xiao、Zhihong Peng、Wanrong Dong、Delie An
DOI:10.1002/ejoc.201501092
日期:2015.12
An efficient method for the formation of C(sp)–N or C(sp)–P bonds is described. The facile transformation proceeds under mild conditions (0 or –20 °C) in a one-pot manner, and does not require transition-metal catalysts. The base-induced protocol exhibits good functional group tolerance (up to 44 examples) and high efficiency (up to 94 % yield) towards rare heteroatom-substituted acetylenes (N or P)