An efficient method to access 2‐triazolyl thio‐/selenopyridines with good to excellent yields by ruthenium(II)‐catalyzedone‐pot [3+2]/[2+2+2] cycloaddition reactions of azides, 1‐alkynyl thio‐/selenocyanates and 1,6‐diynes is reported. This atom‐economical catalytic strategy offers a mild and practical approach to access a variety of such cycloadducts with good to excellect regioselectivities. The
Facile Synthesis of Organic Thiocyanates from Organozinc(II) Thiocyanates and N-Chlorosuccinimide
作者:Kentaro Takagi、Hideaki Takachi、Naomi Hayama
DOI:10.1246/cl.1992.509
日期:1992.3
The reaction of organozinc(II) compounds, generated in situ from organolithiums and zinc(II) thiocyaniate, with N-chlorosuccinimide (NCS) afforded the corresponding organic thiocyanates in good yields.
An atom‐economical approach towards the synthesis of aryl thiocyanates has been documented employing ruthenium‐catalyzed [2+2+2] cycloaddition strategy. Sequential RuII‐catalyzed intermolecular [2+2+2] cycloadditions of 1,6‐diynes and formed aryl thiocyanates resulted in the synthesis of 2‐aryl thiopyridines.
Novel alkynyl(p-phenylene)bisiodonium ditriflates were prepared in good to high yields by reaction of trimethylsilylalkynes with PhIO activated with 2 equivalents of triflic acid. Reaction of the alkynylbisiodonium salts with potassium thiocyanate gave alkynyl thiocyanates in high yields and suggested that the alkynylbisiodonium salts serve as an agent for alkynylation of a nucleophilic substrate.
3-indandione in DMF afforded 2-(1-cyclopentenyl)-2-phenyl-1,3-indandiones in the cases of 1-hexynyl- and 1-octynyl-(p-phenylene)bisiodonium ditriflates. In the reactions of 3,3-dimethyl-1-butynyl-, phenylethynyl-, and trimethylsilylethynyl-(p-phenylene)bisiodonium ditriflates, 2-alkynyl-2-phenyl-1,3-indandiones were obtained. The same reactions with the enolate anion of 2-phenyl-1,3-indandione in a mixed