Thermolyse und einige Reaktionen von 3‐Alkyl‐3,5‐dihydro‐5,5‐dimethyl‐4H‐1,2,3‐triazol‐4‐onen und des 1‐tert‐Butyl‐3,3‐dimethyl‐2‐aziridinons. Ist das acyclische Aziridinon‐Isomere ein Zwitterion?

Abstract

C) and dihydro-1,2,3-triazolone l a (70'C) which quantitatively decompose into acetone and terr-butyl isocyanide (5a) (besides molecular nitrogen in the case of la). In contrast to carlicr reports, 2a docs not produce the a,P-unsaturatcd amidc 7 on heating. werden. Wir fanden ferner ein Reagenz, das mit dem Dihydro-1,2,3-triazolon 1 a anders reagiert als mit dem Aziridinon 2a.Thermolyse des Dihydro-l,2,3-triazolons 1 a und des Aziridinons 2 a Fur die 'H-NMR-spektroskopische Verfolgung von Reaktionen eignen sich besonders N-tert-Butylverbindungen. Wir studierten daher die Thermolyse des 3-tert-ButyldihyChem. Ber. 120, 217-223 (1987) 0 VCH Verlagsgesellschaft mbH,

Time-Resolved IR Detection and Study of an Iminooxirane Intermediate

“…An iminooxirane intermediate was proposed to explain the products of the Lewis acid-catalyzed reaction of a carbonyl compound with an isocyanide . In addition, iminooxirane-derived products were also observed in both the thermal and photochemical decomposition of 3,5,5-trialkyl-3,5-dihydro-4 H -1,2,3-triazol-4-ones. , Quast and co-workers have also reported a comprehensive experimental and computational study of the thermal reorganization and cycloaddition reactions of a stable nonracemic chiral α-lactam, in which they observe iminooxirane-derived products . Using ab initio quantum mechanical calculations of the C 2 H 3 NO potential energy surface, they find that the parent α-lactam is approximately 7 kcal/mol lower in energy than the isomeric iminoxirane.…”

1,1-Diboration of Isocyanides with [2]Borametalloarenophanes

“…The Cp-bound protons of 9 and 10 show eight multiplets ranging from 4.04 to 4.38 ppm and from 4.02 to 4.38 ppm, respectively. The protons of the t -Bu group of 9 show a singlet at 1.44 ppm which is shifted downfield with respect to the resonance at 0.91 ppm for t -BuNC . Likewise, the CH proton of 10 can be detected at 3.31 ppm and thus appears deshielded with respect to the corresponding signal at 2.91 ppm for CyNC, while the remaining protons of the cyclohexyl ring show four complex multiplets between 1.35 and 2.04 ppm.…”

Azide–Enolate Cycloaddition‐Rearrangement Enables Direct α‐Amination of Amides and Enelactam Synthesis from Esters**

“…Several literature reports have proposed that synthetically equivalent reactive intermediates such as aza-oxyallyl cations, iminooxiranes and aziridinones/α-lactams are potentially generated following the extrusion of nitrogen from triazolinones such as 11, or from α-halo amides. [30,51,52] However calculation of relative energies (B3LYP/6-311 + G(d,p)) [30] suggested an appreciable energy barrier (TS NÀ N + 20.8 kJ mol À 1 ) for initial breaking of the NÀ N bond in triazolinone A, disfavouring pathways involving spontaneous nitrogen loss from the initial cycloadduct (see the Supporting Information).…”