Deamination of 1-Alkyl-9-aminomethyltriptycenes. Participation of a Neighboring 1-Alkyl Substituent

Abstract

Deamination reactions of 1-alkyl-9-aminomethyltriptycenes (alkyl = Me, Et, i-Pr, and t-Bu) and 9-(1-aminoethyl)-1-methyltriptycene were performed in CHCl3 and in AcOH, and product distributions were studied. The results suggest that the loss of N2 from a primary alkanediazonium ion predominantly takes place concomitantly with participation of a C–H bond of the neighboring 1-alkyl group to form a nonclassical cationic species with a three-center two-electron bonding, while the loss of N2 from a secondary alkanediazonium ion occurs spontaneously to form a secondary carbocation. Solvent effects (CHCl3 vs AcOH) are explained in terms of lower nucleophilicity/basicity of the AcO− in AcOH than in CHCl3 due to solvation.

Hydrogen Bonding Behavior of Amide-Functionalized α-Diimine Palladium Complexes

“…The monoamide-functionalized α-diimine (2,6- i Pr 2 -Ph)NCMeCMeN(2-C(O)NMe 2 -6- i Pr-Ph) ( 4a ) was synthesized by the route in Scheme starting from 3-isopropylanthranilic acid ( 1 ) . The reaction of 1 with thionyl chloride to generate the corresponding acyl chloride in situ, followed by reaction with aqueous dimethylamine, afforded o -aminobenzamide 2a .…”

“…Toluene- d 8 was purchased from Cambridge Isotope Laboratories and used as received. 3-Isopropylanthranilic acid ( 1 ), N,N,N ′ ,N ′-tetramethyl-2-nitroisophthalamide, α-ketaimine 3 , (cod)PdMeCl (cod = 1,5-cyclooctadiene), and complex 5e were synthesized by literature procedures or modifications thereof.…”

Design, Synthesis and Biochemical Evaluation of Novel Ethanoanthracenes and Related Compounds to Target Burkitt’s Lymphoma

“…Compound To investigate the effect of increased rigidity on the ethanoanthracene bridge, the (E)-9-(2-nitrovinyl)anthracenes (12a-12d) were converted to the corresponding (E)-9-(2-nitrovinyl)-9,10dihydro-9,10-[1,2]benzenoanthracenes (20a-d) in modest yields (Scheme 5, Series V, Table 7). The Diels-Alder reaction was achieved with benzyne as the dienophile generated in situ by thermal decomposition of benzenediazonium-2-carboxylate, (prepared from anthranilic acid and isoamyl nitrite) [56][57][58][59][60]. Diphenyl and triphenyl side products have been reported using in situ benzyne generation [57], but these were not isolated during the current work.…”

Carbocations

“…Deamination of 1-alkyl-9-aminomethyltriptycenes was interpreted in terms of the loss of N 2 from a primary alkane diazonium ion concomitant with participation of a C-H bond of the neighbouring C-H group to form a non-classical carbonium ion with a three-centre, two-electron bond. 162 Non-classical carbonium ions such as corner-protonated cyclopropane were shown by computational methods to be excellent hydrogen bond donors to ammonia. 163 The relevance of such interactions in enzyme-catalysed terpenoid biosynthesis was discussed.…”