Amides adducts

Zoltewicz and co-workers346-349 have shown on the basis of PMR spectral studies that a wide range of nitrogen heteroaromatic cations exist as their pseudobases (e.g., 190-197) in liquid ammonia free of added amide ion. In all cases the PMR spectra of the amide adducts are exactly analogous to those of the corresponding methoxide adducts in methanol.26... 

Kinetic studies suggest essentially zero-order dependence on the substrate concentration, but also indicate a competitive inhibitor function of the product heterocycles. The rapidly formed amine-amide adducts of type Cp2Ln(HNR)(Fl2NR) are assumed to be the active catalyst [161]. The turnover-limiting process is the intramolecular olefin insertion into the Ln-N bond which proceeds via a chairlike, seven-membered transition state (see Scheme 8). As expected, the chiral precatalysts also initiate diastereoselective processes (>95 % de). 

Spencer and gaunt developed a palladium-catalyzed amidation reaction.57 When enone 72 was treated with carbamate Cbz-NH2, in the presence of a catalytic amount of Pd(II), the Wacker addition intermediate underwent a protonolysis rather than the conventional P-hydride elimination process. As a consequence, amidation adduct 73 was obtained as the sole product. 

For stoic reasons, the proton transfo is considerably slower when reaction involves a secondary amine, such as pipoidine, than with a primary amine. Amide adducts such as (53, R =R =H) may also be formed in liquid ammonia [96,152]. Formation of the anilide adduct (53, R =Ph, R =H)in DMSO requires the presence of a strong base, such as DABCO, to effect the proton transfer [153]. TNB does not form zwittoionic adducts from tertiary amines such as triethylamine. However, there is evidence for the formation of species such as (54) where the positive charge is delocalized [153]. Mention has... 

Type Ilb reactions undergo a biomolecular acylation due to the presence of an external nucleophile and are useful with a variety of substrates, including bulky thioacids and amines. Along with the product 405, a recyclable isocyanide-derived side product 406 is also formed. The coupling of thioacid 407 with bulky tert-butyl isocyanide 408 and aniline at room temperature afforded the amide adduct 409 in a 77% yield (Scheme 7.126). 

---