53189-90-5Relevant academic research and scientific papers
A NOVEL AND SIMPLE METHOD FOR THE PREPARATION OF IMINIUM SALTS
Jahn, Ullrich,Schroth, Werner
, p. 5863 - 5866 (1993)
α-Chloroethers such as chloromethyl alkyl ethers of 1,3,3-trichloro-1-isobutoxyprop-2-ene react with trimethylsilyl-N,N-dialkylamines to give the Mannich-reagent and new 3,3-dichloroprop-2-en-1-ylidene-N,N-dialkyliminium chlorides (vinylogous Viehe-reagents), respectively.Extension of this method leads to the reagent system trimethylsilyl-N,N-dialkylamine/trimethylsilylchloride or -triflate, which allows the direct conversion of carbonyl compounds into iminium salts.
New Syntheses of Methyleniminium Salts from Carbonyl Compounds and from α-Chloro Ethers; an Access to Vinylogous Viehe Salts
Schroth, Werner,Jahn, Ullrich,Stroehl, Dieter
, p. 2013 - 2022 (2007/10/02)
Two methods for the synthesis of isolable methyleniminium salts and amidinium salts are presented.In the first case carbonyl compounds A are treated with a mixture of (dialkylamino)trimethylsilane (12) and chlorotrimethylsilane (13) or 12 and trimethylsilyl triflate (14) leading to the iminium chlorides F or iminium triflates G, respectively.With 12/13 the preparation of F is limited to non-enolizable aldehydes and dimethylformamide (10), while 12/14 enables the preparation of G, e.g. 23a-25a, 27a, also with ketones and with substituted amides.The second procedure is based on the treatment of α-chloro ethers L with 12.Both methods afford the Mannich reagent 16a in high yields.By reaction of the α-chloro ether 35 with 12 in diethyl ether the vinylogous Viehe salts 36a-c, e become available for the first time.The reaction pathways are discussed. - Key Words: Methyleniminium salts, preparation, mechanisms of formation / (Dialkylamino)trimethylsilanes / Ethers, α-chloro / Viehe salts, vinylogous
