Palladium-Catalyzed Direct Arylation for the Synthesis of Indeno[2,1-b]-pyrrol-8-ones

Abstract

Treatment of 2-bromophenyl (N-tosylpyrrol-2′-yl)-ketones with Pd(OAc) 2 , Ph 3 P, and K 2 CO 3 resulted in the formation of indeno[2,1-b]pyrrol-8-ones in moderate to good yields.

Synthesis and Some Biological Properties of Pyrrolo[1,2‐a]indoles

“…When trying to synthesize resorcinol 229 , a known precursor in the synthesis of the antibiotic pyoluteorine 230 , the authors of discovered that diketone 231 in the presence of a mixture of mercuric acetate and sodium acetate in acetic acid was transformed into tricyclic 8‐hydroxi‐9 Н ‐pyrrolo[1,2‐ a ]indol‐9‐one 232 with a yield of 85%. Attempts to execute the same reaction in the presence of palladium acetate and triphenylphosphine resulted in a yield of pyrroloindole of only 70% (Scheme ).…”

Cross‐Coupling of Heteroarenes by CH Functionalization: Recent Progress towards Direct Arylation and Heteroarylation Reactions Involving Heteroarenes Containing One Heteroatom

“…[218] In 2012, Chang, Song and co-workers developed a novel approach to indenoA 2 /PPh 3 -catalyzed intramolecular arylation of 2-bromophenyl (N-tosylpyrrol-2-yl) ketones 336, which were obtained by acylation of N-tosylpyrroles 335 with 2-bromobenzoic acids (Scheme 170). [219] Scheme 167. PdA C H T U N G T R E N N U N G (OAc) 2 /dppe-catalyzed intramolecular coupling of compounds 328.…”

“…The intramolecular coupling of 2-bromophenyl pyrrol-2'-yl ketone (338) was also tested and it was found that the reaction produced 9H-pyrroloA C H T U N G T R E N N U N G [1,2-a]indol-9-one (339) resulting from PdA C H T U N G T R E N N U N G (OAc) 2 /PPh 3 -catalyzed intramolecular C À N bond formation (Scheme 171). [219] On the basis of these results it was assumed that the mechanism of the reaction affording compounds 337 very likely involved a direct arylation followed by in situ detosylation. [219] In fact, detosylation followed by intramolecular arylation should have given 9H-pyrroloA C H T U N G T R E N N U N G [1,2-a]indol-9-ones instead of compounds 337.…”

“…[219] On the basis of these results it was assumed that the mechanism of the reaction affording compounds 337 very likely involved a direct arylation followed by in situ detosylation. [219] In fact, detosylation followed by intramolecular arylation should have given 9H-pyrroloA C H T U N G T R E N N U N G [1,2-a]indol-9-ones instead of compounds 337.…”

Efficient and Uncatalyzed Synthesis of Highly Functionalized New Symmetrical Indeno[1,2‐b]pyrroles via a One‐Pot Four‐Component Reaction

“…in 2011 reported an efficient method for the synthesis of various indeno[1,2‐ b ]pyrrole derivatives using Bi‐catalyzed Paal–Knorr reaction of 2‐phenacyl‐1‐indanone. Indeno[2,1‐ b ]pyrrol‐8‐one derivatives were synthesized from the reaction of 2‐bromophenyl ( N ‐tosylpyrrol‐2′‐yl)‐ketone derivatives with palladium(II) acetate, triphenylphosphine, and potassium carbonate . Perumal et al .…”