Notiz über die Bildung von Keten‐aminalen aus Orthocarbonsäureestern

The Modes of Reaction of Ambident Catioins

“…Nevertheless, it is surprising that the amidinium ion itself (154) is not attacked by lithium dimethylamide in boiling ether [%I. Trisdialkylaminomethanes such as (155) cannot be isolated, in agreement with other attempts of synthesis[56,57], because the resonance energy of the amidinium ions is too great.the favored position of formaldehyde in the Mannich reaction, which proceeds via (138) [50], and also the limitation of the Vilsmeier reaction to formylamines. If in the latter reaction, the intermediate (147) contains an alkyl group, partial deprotonation again occurs and hence dimerization of both partners takes place [29].…”

“…can be obtained from carboxylic acids, (3amino alcohols, and thiophenols in a single-stage synthesis [24b]. The amide(55) initially formed undergoes ring closure to form the basic oxazoline (56) which then reacts as a cation with the thiophenoxide ion to form the thioether(57). The steps A + B twice repeated finally lead to the product(58).…”

Morpholine Ketene Aminal as Amide Enolate Surrogate in Iridium‐Catalyzed Asymmetric Allylic Alkylation

“…Morpholine ketene aminal 2 was readily synthesized from the corresponding orthoester and secondary amine following the procedure reported by Baganz and Domaschke in 1962 . In initial prospecting experiments with unprotected allylic alcohols as starting material, [Ir(cod)Cl] 2 (2.5 mol %), L1 (10 mol %), and 2 (1.2 equiv) were found to lead to decomposition of the nucleophile.…”

Boron trihalide adducts of 1,1-bis(piperidinyl)ethylene. 13C and 11B nmr studies of a model system for β-carbon donation in enamine adducts

“…1,1, I-triethoxyethane and piperidine in the presence of toluene-4-sulfonyl chloride, according to the method of Baganz and Domaschke (26). Freshly distilled 4 is clear and colorless but it discolors on standing.…”