Pyridine synthesis from oximes and alkynesviarhodium(<scp>iii</scp>) catalysis: Cp* and Cp<sup>t</sup>provide complementary selectivity
作者:Todd K. Hyster、Tomislav Rovis
DOI:10.1039/c1cc15248c
日期:——
The synthesis of pyridines from readily available α,β-unsaturated oximes and alkynes under mild conditions and low temperatures using Rh(III) catalysis has been developed. It was found that the use of sterically different ligands allows for complementary selectivities to be achieved.
bisacylphosphine oxide photoinitiator was used for the light mediated preparation of palladium nanoparticles (PdNPs) with a small diameter of 2.8 nm. All starting materials are commercially available, and PdNP synthesis is experimentally very easy to conduct. The PdNP-hybrid material was applied as catalyst for the semihydrogenation of various internal alkynes to provide the corresponding alkenes in excellent yields
Highly Regio- and Stereoselective Synthesis of Tetrasubstituted Cyclobutenes via Cyclodimerization of Alkynes Mediated by Zirconium
作者:Yuanhong Liu、Meina Liu、Zhiquan Song
DOI:10.1021/ja042636m
日期:2005.3.1
Zirconium-induced cyclodimerization of a variety of heteroaryl-substituted alkynes is described. This method provides a facile synthesis of tetrasubstituted cyclobutenes with high regio- and diastereoselectivity. A ligand-induced reductive elimination mechanism accounting for this novel cyclodimerization is suggested.
approach toward trisubstituted allenes through Pd-catalyzed alkynyl Heck coupling reaction of alkynes and aryl iodides is reported. This process proceeded via regioselective carbopalladation of 1-aryl-1-alkynes to give alkenyl palladium species, which undergo β-hydride elimination to provide 1,1-diarylallenes in 25-71% yields. This method features unique regioselectivity and high functional group compatibility
Synthesis of α-Diketones from Alkylaryl- and Diarylalkynes Using Mercuric Salts
作者:Michael E. Jung、Gang Deng
DOI:10.1021/ol500592m
日期:2014.4.18
Both alkylarylalkynes and diarylalkynes 1 are converted into the alpha-diketones 2 in good yield by the use of mercuric salts, e.g., mercuric nitrate hydrate or mercuric triflate, in the presence of water. Other mercuric salts, e.g., sulfate, chloride, acetate, or trifluoroacetate, do not provide the diketone product. A possible mechanism is proposed.