Facile synthesis of annulated heterocyclic benzo[kl]acridine derivatives via one-pot N–H/C–H coupling

Abstract

A facile and efficient synthesis of benzo[kl]acridines was developed based on a domino reaction via a combinatorial catalyst approach.

Recent Advances in Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds

“…In 2016, Li and co-workers developed an efficient N–H/C–H one-pot coupling method for the preparation of benzo[ kl ]acridines, including the N,S- and N,O-containing benzoperylenes 45.3 and 45.4 , respectively ( Scheme 45 ). 76 This strategy is based on the reaction of 1,8-dibromonaphthalene 45.1a or 1,8-diiodonaphtalene 45.1b with a secondary aromatic amine. The reaction was proposed to proceed via Buchwald–Hartwig amination followed by intramolecular C–H arylation.…”

“…(for details, see Scheme 45 , Section 3.1.2 ) was also applicable to the annulation of 5 H -dibenzo[ b , f ]azepine ( 294.1 ). 76 As shown in Scheme 294 , the use of either 1,8-dibromo- or 1,8-diiodonaphthalene as the coupling partner under the optimized reaction conditions could lead to the [ de ]annulated dibenzoazepine 294.2 in 79–83% yield. The nonplanar geometry of 294.2 was established by X-ray crystallography.…”

“… Reagents and conditions: (a) 76 t -BuONa, Pd(OAc) 2 (3 mol %), Pd 2 (dba) 3 (3 mol %), PCy 3 (7 mol %), t -Bu 3 P (7 mol %), dry toluene, 90 °C, 10 h; (b) 558 Pd(OAc) 2 (10 mol %), PPh 3 (20 mol %), norbornene (1 equiv), Cs 2 CO 3 (4 equiv), toluene, 95 °C, 6 h; (c) 559 PdCl(C 3 H 5 )(dppb) (2 mol %), KOAc (2 equiv), DMA, 150 °C, 72 h. …”

“… a Reagents and conditions: (a) t -BuONa, Pd­(OAc) 2 , Pd 2 (dba) 3 , Cy 3 P, ( t -Bu) 3 P, toluene, 90 °C, 10 h. …”

“…Schemes , Section , and , Section ), can be assembled in several ways, e.g., using the previously discussed tandem cross-coupling annulation reported by Li et al ( 183.2 , Scheme ). In this synthesis, Buchwald–Hartwig amination was presumed to precede the arylation step. An alternative approach, employing nucleophilic aromatic substitution in the ring-forming step, was used by Zeng et al to prepare the NIR fluorescent rhodamine dye 183.4 …”