Paracyclophanes: Extending the Bridges. Reactions

Abstract

[m.n]Paracyclophanes with bridges of equal and unequal length (m,n Յ 4) undergo electrophilic aromatic substitution (Friedel-Crafts acylation, bromination) under very mild conditions as long as the bridge contains less than four atoms. Whenever there is a choice, the aromatic ring is attacked at the position closest to the shorter alkano bridge, which indicates that the transannular benzene moiety acts as a neighboring group. By brominating the acetyl derivatives obtained, and the acids and esters derived therefrom, a second substituent is introduced into the pseudo-geminal position, that is, directly opposite the directing group. However, this

Self-Assembling [n.n]Paracyclophanes: A Structure–Property Relationship Study

“…HRMS (ESI) m / z : [M – H] − calcd for C 19 H 19 O 2 : 279.1391, found 279.1403. 1 H NMR and 13 C NMR are consistent with literature values …”

“…1 H NMR (400 MHz, chloroform-d) δ 7.56−7.44 (s, 1H), 6.87−6.62 (m, 6H), 3.80 (m, 1H), 3.08−2.45 (m, 7H), 2.31−1.99 (m, 4H). 13 57 (±)-5-(n-Hexyl)amide [3.3]paracyclophane ((±)-3). This compound was synthesized in the same way as (±)-1a with (±)-9 (256 mg, 0.913 mmol), oxalyl chloride (0.29 mL, 3.6 mmol), and DCM (20 mL).…”