Chemistry of aminimides

Penta- and hexacoordinate silicon mixed dichelates with the SiC2O2N(Cl) ligand environment

“…The location of charges in 5a (and by analogy in 5b) is not as obvious: 5 may be an ion pair with positive charge residing on the ammonium nitrogen atom, or it may have two positive charges, one on nitrogen and one on silicon (with similar charge distribution by the donor ligands) and two corresponding negative charges, on chloride and the amide nitrogen. The close similarity of general geometry and bond lengths in the two crystals (5a and 16), suggests that both have similar positive charge distributions around silicon, and that the N-NMe 2 moiety in 5a constitutes a separate and independent zwitterionic "aminimide" fragment, 11 which has little effect on charges in other parts of the molecule. This implies that 5a should be better represented by the formula 5a', and is hence considered a donor-stabilized silyl cation.…”

Pyrolysis of hydrazine derivatives and related compounds with N N single bonds

“…The reactions forming cyclic aminimides are reversible in many cases: pyrolysis of N,N-disubstituted aminimides 159 can regenerate the isocyanatoamines 160, which can then be trapped with other isocyanates. However, elimination of an alkene (forming 161) or a thermal Stevens-type 1,2-migration of an alkyl group to form 1,2-disubstituted 1,2,4-triazole-3,5-diones 162 can also take place (Scheme 44) [142]. The 1,2-migration may involve homolysis of an R-N bond.…”

“…The dialkylamino radicals, formed either thermally or photochemically in solution, can be used as initiators for radical polymerization [177] The reaction of the dimethylamino radical with toluene and substituted toluenes yielded a Hammett value of -1.08 for the abstraction reaction giving R 2 NH and a deuterium isotope effect of 4.0. The rate of the thermal decomposition of tetramethyl-2-tetrazene (TMT) in benzene solution at [126][127][128][129][130][131][132][133][134][135][136][137][138][139][140][141][142] o C were of the order 10 -5 -10 -4 s -1 with an approximate energy of activation of 45 kcal/mol -rather high compared with the gas-phase values given above. Importantly, however, at concentrations of TMT greater than 0.2 M, induced decomposition of the tetrazene becomes important [178].…”

Cycloaddition Reactions of 1-Aza- and 1,3-Diazaazulenium 1-Methylides

“…Heteroaromatic N-ylides [1][2][3] and heteroaromatic N-imines [4][5][6][7][8] , which are highly useful synthetic intermediate for the construction of fused heterocycles via 1,3-dipolar cycloaddition reaction. 9,10 We previously reported about the synthesis and reactions of 1-azaazulene N-imine (1) where interesting dipolar cycloadditions were observed.…”