Thermal and microwave‐assisted [3+2] cycloadditions between differently substituted propiolamidinium tetraphenylborates 3a–d and N‐methyl‐C‐phenylnitrone, benzyl azide, and N‐(3‐azidopropyl)phthalimide were studied. The activation parameters of the [3+2] cycloaddition between alkyne 3a and benzyl azide were determined. A Diels–Alder reaction between the terminal alkyne 3a and cyclopentadiene could be achieved with the aid of microwave activation. The reaction between 3a and triphenylphosphorane imine provides the β,β‐bis(dimethylamino)vinylphosphonium salt 21, which might or might not have been formed through an initial [2+2] cycloaddition reaction.
The solid-state structure of chlorido [2-(N,N,N ,N -tetramethylamidinio)ethynido]silver (3), obtained by C(sp)-metalation of N,N,N ,N -tetramethyl-propiolamidinium chloride with silver(I) oxide, has been determined by X-ray diffraction analysis. A comparison of bond lengths in the propiolamidinium moiety with those of the two genuine propiolamidinium salts 4 and 5, as well as with data for the isolated N,N,N ,N -tetramethyl-propiolamidinium cation obtained by quantum-chemical calculations, has been made. It can be concluded that complex 3 is better described as a (tetramethylamidinio)ethynyl than as a 3,3-bis(dimethylamino)allenylidene silver complex.
Starting from N,N,N¢,N¢,N¢¢,N¢¢-hexaalkylguanidinium chlorides and terminal alkynes, a series of new orthoamide derivatives of alkynecarboxylic acids were prepared. The orthoamides were converted into propiolamidinium chlorides by reaction with benzoyl chloride and into propiolamidinium triflates by reaction with triethylsilyl trifluoromethanesulfonate. Propiolamidinium salts undergo conjugate addition reactions with sec-amines and thiols. Treatment of terminal alkyne chlorides with silver(I) oxide afforded a silver complex, which can apparently adopt the composition of either a bisalkynyl silver complex [Ag(CCC(NMe 2 ) 2 ) 2 ]AgCl 2 or a monoalkynyl silver complex [ClAgCCC(NMe 2 ) 2 ].
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.