New Formylating Agents − Preparative Procedures and Mechanistic Investigations

Abstract

The reactivity of new formylating agents related to formamide has been investigated both experimentally and theoretically. The reaction in 1,2-dichloroethane between tris(diformylamino)methane (2) and several arenes, catalyzed by AlCl 3 or BCl 3 , was shown to proceed in good yields to afford the corresponding para-substituted aldehydes. The nature of the active electrophilic species was also investigated theoretically. Thus, the relative stability of the O-and N-protonated forms, as well as those of AlCl 3 adducts, of several formylat-

ortho-Formylation of oxygenated phenols

“…C-2 is deprotonated if phenyl lithium, n-BuLi or sodium sand is used as reagent; subsequently adding DMF or N-methyformanilide yields the C-2 formylated product. [185][186][187][188][189] While C-4 is formylated when Gattermann/Adams, 151,152 Gross,190 Vilsmeier-Haack [191][192][193] or reaction methods derived thereof 194,195 are employed. Yields are in the range of 45-99%.…”

New Methods for the Preparation of Aromatic Aldehydes

“…Triformamide is accessible by formolysis of tris(dichloromethyl)amine ( 10 ), but tris(dichloromethyl)amine ( 10 ) itself can be viewed as a formylating reagent in the presence of Lewis acid 33,37. The compound is not ionised but is structurally closely related to the iminium chloride 1 used in Vilsmeier−Haack formylation reactions.…”

Superacidic Activation of α,β‐Unsaturated Amides and Their Electrophilic Reactions

“…The analogous reactivity of α,β‐unsaturated amides has not thus far been investigated. However, superacidic activation of the amides could involve their O ‐protonation16,17 or O ‐complexation18 with Lewis acid, with subsequent additional protonation of C=C (or C≡C) bonds. Thus, it was recently shown that cinnamanilide 5 cleanly undergoes intramolecular cyclization in triflic acid to give quinolinone 6 in good yield 19.…”