Chalcogen controlled redox behaviour in peri-substituted S, Se and Te naphthalene derivatives

Abstract

Cyclic and square wave voltammetry of (PhE)2 peri-disubstituted naphthalene[1,8-cd]dichalcoganyls and acenaphthene[5,6-diyl]dichalcoganyls (E = S,Se,Te, 12 compounds), is reported. Mixed E1 = Se,Te; E2 = Br,I) naphthalene[1,8-cd]halochalcoganyls were also investigated, as...

Incipient Nucleophilic Attack on a Carbonyl Group Adjacent to a Stereogenic Centre in Peri Naphthalene Derivatives

“…τ Me [°] 14 [44] 1.514(3) À 86.3(3) 156.9 37.4(3) 13 (Figure 4). [44] The disposition of the carbonyl group is a little different from that in the dimethylamino series and also in the hydroxy naphthalenes 12 and 13: the torsion of the carbonyl group with respect to the naphthalene ring is reduced to 54.2(2)°compared to 64.14 (16) to 77.50 (19) 2). The orientations of the groups at the stereogenic centre are very similar indeed in the three dimethylamino analogues.…”

“…Examples include a NMe 2 or OMe group with an aldehyde, alkene, alkyne or nitrile, [5–8] hydrogen bonding to an amide nitrogen atom [9,10] or to a π‐surface, [11] novel Si−H⋅⋅⋅B bonds, [12] construction of abnormally long bonds, [13] methods for determining the degree of bonding between peri‐ groups, [14] and the promotion of reactions between groups held close together [15] . Peri‐ naphthalenes also occur in some proton sponges, [16] and systems with frustrated lone pairs, [17] while peri ‐acenaphthenes have been used to investigate interactions between the heavier main group elements [18,19] . Particularly notable investigations have involved substitution reactions at silicon, [20] characterisations of the interaction of a −F group, or reaction of a thiolate group, with an amide carbonyl group, [21,22] a system for the release of S=O from a peri ‐naphthalene [23] and a recent study of a 1,5 hydride shift facilitated by peri ‐interactions [24] …”

“…[15] Peri-naphthalenes also occur in some proton sponges, [16] and systems with frustrated lone pairs, [17] while peri-acenaphthenes have been used to investigate interactions between the heavier main group elements. [18,19] Particularly notable investigations have involved substitution reactions at silicon, [20] characterisations of the interaction of a À F group, or reaction of a thiolate group, with an amide carbonyl group, [21,22] a system for the release of S=O from a peri-naphthalene [23] and a recent study of a 1,5 hydride shift facilitated by peri-interactions. [24] The studies on a series of peri-naphthalene and -acenaphthenes representing an aza-Michael reaction (Me 2 N/C=CZ 2 , Z = electron-withdrawing group), with interactions ranging from initial n-π* interaction to partially completed bond formation has led to the construction of a reaction pathway and to measurement of bonding charge density between reacting groups as the bond forms.…”

N,N’‐Diaryl‐Sulfurdiimides are Strongly Redox Tuned

“…The calculated energies without empirical dispersion corrections conform to the proposed conformations, namely E/Z being the lowest energy conformation for 1 – 7 , and Z/Z the lowest energy conformation for 8 and 9 (Table 1). When dispersion correction is added, the lowest energy conformation for all of the sulfur diimides becomes Z/Z, reflecting a known tendency of D3BJ to overestimate (intramolecular) π‐stacking interactions between pendant aryl rings attached to thiazyls [44–45] . As there is convincing UV‐vis and NMR evidence for compounds 1 – 7 being predominantly E/Z in solution, it seems likely that similar overestimation of π‐stacking stabilization is operative for D3BJ correction in aryl SDIs.…”

“…When dispersion correction is added, the lowest energy conformation for all of the sulfur diimides becomes Z/Z, reflecting a known tendency of D3BJ to overestimate (intramolecular) π-stacking interactions between pendant aryl rings attached to thiazyls. [44][45] As there is convincing UV-vis and NMR evidence for compounds 1-7 being predominantly E/Z in solution, it seems likely that similar overestimation of π-stacking stabilization is operative for D3BJ correction in aryl SDIs.…”