3‐diynes is described. Key for the success of this novel transformation is the utilization of an advanced palladium catalyst system with the specific ligand Neolephos. The synthetic value of this general approach to synthetically useful α‐alkynyl‐α, β‐unsaturated amides is showcased by diversification of several structurally complex molecules and marketed drugs. Control experiments and density‐functional
Synthesis of 2,3,6-trisubstituted pyridines by transition-metal free cyclization of 1,3-diynes with amino acids
作者:Gang Zhou、Xiaoming Zhao、Wenyan Dan
DOI:10.1016/j.tetlet.2017.06.080
日期:2017.8
Amino acids are firstly employed in transition-metal free heterocyclization reaction of 1,3-diynes in the presence of K3PO4 and DMSO at 120 °C. This method produces 2,3,6-trisubstituted pyridines with up to 86% yield. The –CO2H group on the amino acids is crucial for this heterocyclization reaction. The mechanism of such a heterocyclization reaction is discussed, as well.
首先在120°C下在K 3 PO 4和DMSO存在下,将氨基酸用于1,3-二炔的无过渡金属的杂环反应中。该方法产生2,3,6-三取代的吡啶,产率高达86%。氨基酸上的–CO 2 H基团对于该杂环化反应至关重要。还讨论了这种杂环化反应的机理。
Copper-Catalyzed Aerobic Oxidative Transformation of Ketone-Derived<i>N</i>-Tosyl Hydrazones: An Entry to Alkynes
A novel strategy involving Cu‐catalyzedoxidative transformation of ketone‐derived hydrazone moiety to various synthetic valuable internal alkynes and diynes has been developed. This method features inexpensive metal catalyst, green oxidant, good functional group tolerance, high regioselectivity and readily available starting materials. Oxidative deprotonation reactions were carried out to form internal
Catalytic, Regioselective Hydrocarbofunctionalization of Unactivated Alkenes Triggered by <i>trans</i>-Acetoxypalladation of Alkynes
作者:Rahul K. Shukla、Atul K. Chaturvedi、Subir Pal、Chandra M. R. Volla
DOI:10.1021/acs.orglett.1c00118
日期:2021.2.19
Herein we demonstrate a Pd(II)-catalyzed regioselective hydrocarbofunctionalization of unactivatedalkenes. The σ-vinyl-palladium(II) intermediate generated by the trans-acetoxypalladation of alkynes was added across carbon–carbon double bond to realize an efficient hydroalkenylation protocol. Bidentate auxiliary 8-aminoquinoline controls the regioselectivity of the carbopalladation step and thereby
Efficient and Reusable CuI/1,10-Phenanthroline-Catalyzed Oxidative Decarboxylative Homocoupling of Arylpropiolic Acids in Aqueous DMF
作者:De-Xian Liu、Fei-Long Li、Hong-Xi Li、Wei-Jie Gong、Jun Gao、Jian-Ping Lang
DOI:10.1002/ejoc.201402416
日期:2014.8
An efficient method for synthesis of 1,3-diynes through the CuI/1,10-phenanthroline-catalyzedoxidativedecarboxylativehomocoupling of aryl pioprolic acids in aqueousDMF has been developed. The catalytic system was suitable for a variety of arylpropiolicacids, and the corresponding 1,3-diynes could be prepared in high yields. The catalytic system was recovered from the organic products by filtration