Metal/Benzoyl Peroxide (BPO)-Controlled Chemoselective Cycloisomerization of (o-Alkynyl)phenyl Enaminones: Synthesis of α-Naphthylamines and Indeno[1,2-c]pyrrolones

Abstract

Synthetic methods involving chemoselective tandem reactions for the synthesis of α-naphthylamines and indeno[1,2-c]pyrrolones starting from (o-aklynyl)phenyl enaminones are described. When reactions were carried out in N,N-dimethylformamide (DMF) using a AgNO catalyst, α-naphthylamines were obtained in up to 89% isolated yields within 2 h. Whereas indeno[1,2-c]pyrrolones were produced in high isolated yields in the presence of benzoyl peroxide (BPO) and CuCl catalysis.

TBAF-Catalyzed O-Nucleophilic Cyclization of Enaminones: A Process for the Synthesis of Dihydroisobenzofuran Derivatives

“…(If the filtrate still contained a small amount of 2 in individual substrates judging by TLC, the small amount of product could be recovered by column chromatographic purification using petroleum ether/ethyl acetate (from 15/1 to 5/1, v/v) as the eluent.) Compounds 2b−g, 2k−m, and 2o are known compounds, 19 and the spectroscopic data are in agreement with that previously reported. The analytical data of other products 2 are as follows.…”

“…The compounds 2 were prepared according to the literature methods. 19 To a solution of 7 19 (4.4 mmol) in MeOH (5 mL) in an oven-dried vial was added NH 2 R 1 (1.02 equiv), and the mixture was stirred at room temperature in the air for 1−2 h until 7 had disappeared by TLC analysis. Then, the mixture was filtered, and the filter cake was washed with methanol (5 mL).…”

“…17a As part of our ongoing efforts to develop new methodology for the construction of carbo-and heterocyclic compounds, 18 we previously disclosed synthetic methods involving chemoselective tandem reactions for the synthesis of α-naphthylamines and indeno [1,2-c]pyrrolones starting from (o-alkynyl)phenyl enaminones (Scheme 1, d). 19 Further, we designed (oterminal alkynyl)phenyl enaminone 2a′ (Scheme 2) and envisioned that it might be feasible to prepare other potentially useful ring-fused cyclic products via a C sp2 −H functionalization. However, when TBAF was used to remove trimethylsilyl, no 2a′ was observed, and C-nucleophilic cyclization product (such as 3a) was not detected.…”

Rapid, microwave-assisted synthesis of Gd2O3and Eu:Gd2O3nanocrystals: characterization, magnetic, optical and biological studies

“…Such behaviour has also been observed for Gd 2 O 3 nanosheets. 36 It is also known that, in ultra-small nanoparticles of the ferromagnetic metals iron, nickel and cobalt, there is a 10-30% enhancement of surface magnetic moments over their bulk values. 37 However, at room temperature (300 K), the M vs. H plot [Fig.…”

Silver‐Catalyzed Sequential Cascade Reaction of Isocyanides with 1‐(2‐Ethynyl‐phenyl)‐prop‐2‐yn‐1‐ol: Access to Benzo[b]fluorenes and Benzofuran‐Pyrroles

“…Typical synthetic procedure for 1 : To a solution of substituted 2‐bromobenzaldehyde (5 mmol) in Et 3 N (10 mL) in Schlenk tube was added Pd(PPh 3 ) 2 Cl 2 (2 mol%, 70.2 mg) and CuI (5 mol%, 47.6 mg), and stirred at room temperature for 10 min under nitrogen. Then, substituted acetylene (1.2 equiv.)…”