60455-11-0Relevant academic research and scientific papers
N-heteroarylium Salts in Synthesis, 3 Intramolecular ortho-Acylation of Some N-Heteroaromatic Ring Systems
Anders, Ernst,Boldt, Hans Guenter,Clark, Timothy,Fuchs, Renate,Gassner, Thomas
, p. 279 - 296 (2007/10/02)
The title compounds 17 (prepared by methods A-C) have been reacted with sodium bis(trimethylsilyl)amide (18) in a heterogeneous mixture (-80 deg C, 2-60 h).The ortho-substituted N-heteroaromatic compounds 4 are isolated exclusively after an intramolecular and regiospecific reaction .This method represents the first widely applicable acylation technique for N-heteroaromatic compounds in which the incoming substituent (R1CO) functions as an internal electrophile and in which the formation of isomeric or polyacylated products has not yet been observed.Both experimental and theoretical (MNDO) investigations show that the substitution reaction (5) is primarily determined by the conformational and electronic properties of the deprotonation product 25 , which is formed preferentially.
phosphonium Salts, 4: Synthetic Methods
Anders, Ernst,Gassner, Thomas,Stankowiak, Achim
, p. 124 - 131 (2007/10/02)
Four syntheses A - D are described for the phosphonium salts 1, which are precursors of the highly reactive phosphoranes 3.Whereas the usual method B fails in some cases it is now possible to prepare 1 with a wide variety of substituents R1, R
