Reactions and interactions between peri-groups in 1-dimethylamino-naphthalene salts: an example of a “through space” amide

Abstract

Abstract8-Dimethylaminonaphthalene-1-carbaldehyde reacts readily at 0°C with benzoyl or pivaloyl chloride by O-acylation and formation of a N–C bond (1.566(2)–1.568(3) Å) between the peri-substituents to give a salt. The reaction is promoted by electron donation from the dimethylamino group to the carbonyl group, akin to the properties of an amide. In contrast, the corresponding methyl ester and N,N-diisopropylamide react with acid in ether by protonation of the dimethylamino group and formation of a hydrogen bond to the carbonyl group, while under similar conditions the N,N-dimethylamide undergoes ready hydrolysis to the acid. The structures of products are determined by X-ray crystallography, and from the latter hydrolysis crystals containing zwitterionic 1-dimethylammonium-naphthalene-8-carboxylate and the corresponding O-protonated cation along with dimethylammonium and triflate ions were obtained.

Interaction, bond formation or reaction between a dimethylamino group and an adjacent alkene or aldehyde group in aromatic systems controlled by remote molecular constraints

“…3, Table 3). The phenyl groups have enhanced the difference in the exo angles ψ and φ between the peri-positions from 14.4 o in naphthalene salt 5 5 which (Fig. 3).…”

“…the dimethylamino aldehyde 4 protonates on oxygen, not nitrogen, with HCl to give salt 5 with formation of a N-C bond. 4,5 Studies have been extended to interactions between electron-rich centres and electrophilic polar multiple bonds such as alkynes, nitriles and alkenes in 6-8. [6][7][8][9][10] The interactions between a dimethylamino group and a range of polarised alkenes has been studied the most intensively.…”

Modelling of an aza-Michael reaction from crystalline naphthalene derivatives containing peri–peri interactions: very long N–C bonds?

“…12 Attractive interactions between functional groups were first reported in the pioneering work from Dunitz et al on the interactions of nucleophiles with carbonyl groups as in naphthalene 1. 13 Such n-π* interactions affect the chemistry of the electrophile, for example the aldehyde 2 both protonates and acylates on the O atom with formation of a N-C bond between the two groups, 14 as do several closely related ketones. 15 We have reported the structure of a series of compounds where a dimethylamino group lies next to a polarised alkene, such as 3 and 4.…”

5-Chloro-8-nitro-1-naphthoyl (NNap): A Selective Protective Group for Amines and Amino Acids

“…Primary and secondary amines were tested: noctylamine ( 5), n-decylamine (6), and benzylamine (7) afforded, in 30 min, a quantitative NMR yield of the desired amides (86−95% isolated yields). The more hindered primary amine tert-octylamine (8) and the secondary amine di-nbutylamine ( 9) also gave the corresponding amides in high yields (87−90% isolated yields). To further explore the substrate scope, an aromatic amine, 4-tert-butylaniline (10), was tested; as shown in Table 1 (entry 6), the aniline 10 was easily transformed to the target amide in 91% isolated yield under the same reaction conditions.…”

“…The X-ray crystal structure of 8-(dimethylamino)-1-naphthyl methyl ketone 6 illustrates the Burgi-Dünitz trajectory in which the combination of the steric compression and the bonding interaction between the lone pair of the amine and the carbonyl group deforms the molecule ( Figure 1 B). 7 Another example is the high reactivity of 8-dimethylamino-1-naphthaldehyde, in which treatment with benzoyl chloride 8 leads to benzoylation of the aldehyde oxygen and addition of the peri -dimethylamino group to the former carbonyl group, setting a new N–C bond ( Figure 1 C).…”