Preparation of (Z)-1-fluoro-1-alkenyl carboxylates, carbonates and carbamates through chromium mediated transformation of dibromofluoromethylcarbinyl esters and the reactivity as double acyl group donors
CrCl2/Mn-mediated transformation of various dibromofluoromethylcarbinyl esters including carboxylates, carbonates and carbamates provided 1-fluoro-1-alkenyl esters via [2,3]-sigmatropic rearrangement of ester group. Reaction proceeded by using CrCl2/Mn system under mild conditions (in THF at room temperature) to give 1-fluoro-1-alkenyl esters in good yield with an excellent Z selective manner. 1-Fluoro-1-alkenyl
been developed as chemoselective N-acylation reagents. Selective protection of primary amines in the presence of secondary amines, acylation of aliphatic amines in the presence of aryl amines, and monofunctionalization of primary-secondary diamines as well as selective N-acylation of amino alcohols using these reagents are described. All of the acylation reactions were carried out in water as a green
Well-dispersed palladium (0) nanoparticles stabilized with phosphonium based ionic liquid were synthesized conveniently and fully characterized. A catalyst system comprising of the Pd(0) nanoparticles and a base was found to be recyclable and efficient for the aminocarbonylation reaction of aryl iodide in ionic liquid media. In the presence of potassium tert-butyloxide, for the relatively stable aryl chloride and bromide substrates, medium activities were achieved for the catalyst. The catalyst composites can be recycled at least five times with sustained activity.
Efficient and continuous monoacylation with superior selectivity of symmetrical diamines in microreactors
作者:Ram Awatar Maurya、Phan Huy Hoang、Dong-Pyo Kim
DOI:10.1039/c1lc20765b
日期:——
Efficient and continuous monoacylation of symmetricaldiamines performed in microreactors yielded superior selectivity to that predicted by statistical considerations. It is highly valuable that the kinetically controlled product in high yields was achieved without any special catalyst at ambient temperature.