Synthese und Struktur von N ‐Acylimidsäureestern

Abstract

Synthesis and Structure of Alkyl N-AcylimidatesAlkyl N-acylimidates 1 are prepared more easily and in higher yields than before by reaction of alkyl imidate hydrochlorides 5 with acyl halides 7 in the presence of 2.2 mol of base (14 examples). The X-ray analysis of a crystalline derivative (ldbd) shows, that the C=N-and the C = 0 parts are twisted significantly (torsional angle 77.6"). The stereochemical, dynamic, and electronic properties of the compounds 1 are interpreted by means of ab initio 3-21 G calculations on conformers of the parent system HO -CH = N -CH = 0 (8). Low rotational (ca. 6 kcal/mol) and inversional (max. 8 kcal/mol) barriers indicate the many favourable electronic interactions between the C = N-and the C = 0 groups in such N-functionalised imine dcrivatives. The compounds 1 are significantly higher in energy than bisacylamines and are therefore suggested to be superior, more reactive synthetic C -N -C building blocks. The spectroscopic properties (IR, 13C-and 'H NMR, MS) arc given and discussed.I N-Acylimidsaureester 1, die durch die Atomreihung -0 -C = N -= 0 gekennzeichnet sind, lassen auf Grund ihrer Haufung an funktionellen Zentren zahlreiche Reaktionsmoglichkeiten erwarten. So bieten sich z. B. fur nucleophile Ang r s e die Kohlenstoffatome der Carbonyl-und der Imidfunktion an. Auf diese Weise konnten eine Reihe fiinf-und sechsgliedriger Heterocyclen synthetisiert 0 VCH Verlagsgesellschaft mbH, D

Modular Routes Towards New N,O‐Bidentate Ligands Containing an Electronically Delocalised β‐Enaminone Chelating Backbone

“…Like in the case of compounds 9-11 the E/Z ratio of the 3-amino-2-enenitrile does not matter when introducing R 1 (24)(25)(26)(27)(28)(29)(30) by reaction with acyl chlorides or anhydrides, respectively: the newly formed hydrogen bond directs the product into Z configuration (see Scheme 2). In the case of 30, also the N-acylated product was observed (31).…”

Electrophilic Reactivity of a 2-Azaallenium and of a 2-Azaallylium Ion

“…-NMR spectroscopy: Bruker WM 300 and WM 360, internal standard tetramethylsilane (TMS, δ ϭ 0.00 ppm). [22] (1.95 g, 10.2 mmol) was dissolved in acetonitrile (20 mL) and cooled to 0°C…”

Synthesis of Secondary, Tertiary and Quaternary 1,3,5‐Triazapenta‐1,3‐dienes and Their CoII, ZnII, PdII, CuII and BF2 Coordination Compounds

“…Therefore, for the synthesis of 1,3,5-triazapenta-1,3-dienes with aromatic substituents a new reaction pathway based on N-imidoylimidoates 5, the nitrogen analogues of N-acylimidoates, [18] was developed (Scheme 4). Up to now only one synthetic route for them is known.…”

“…The compound was obtained from ethyl benzimidoate hydrochloride [18,25] (8.83 g, 47.6 mmol) and N-phenyl-4-nitrobenzimidoyl chloride [33] (12.40 g, 47.6 mmol) in dry chloroform. The crude product was purified by column chromatography (pen- ) …”

“…From ethyl benzimidoate hydrochloride [18,25] (1.86 g, 10.0 mmol) and N-phenylbenzimidoyl chloride [18,26] X-ray Crystal Structure Analysis for 5a: [27,28] Ethyl Benzenecarboximidoate Derivative 5b: This compound was obtained from ethyl benzimidoate hydrochloride [18,25] (1.86 g, 10 mmol) and N-phenyl-pivalimidoyl chloride [29] (1. [30] (1.50 g, 10 mmol) and N-phenylbenzimidoyl chloride [26] …”