Boron Trifluoride Catalyzed Divergent Synthesis of 3‐Alkenyl‐3‐amino‐2‐oxindoles and Spiro‐indeneindolones from Propargylic Alcohols

Abstract

An expedient method was demonstrated for the synthesis of 3-alkenyl-3-amino-2-oxindoles from readily available propargylic alcohols and isatin imines in the presence of BF 3 · Et 2 O as a catalyst under open-air atmosphere. The above reaction was time-dependent and further extended to the one-pot synthesis of highly substituted spiroindeneindolones via 1,3-amino group migration/ Friedel-Crafts cyclization. This methodology, which tolerates a broad variety of functional groups, offers versatile and atom-economical access to 3-alkenyl-3-amino-2-oxindole or spiro-indeneindolone derivatives in good yield at room temperature.

Iodine-catalyzed Synthesis, Antibacterial, and Antioxidant Activity of Isatin Derivatives

“…Synthesis of isatin derivatives compounds has been carried out in various ways, including using catalysts. Some catalysts that have been used in the synthesis of isatin derivatives are palladium [16], Ru(II)-Pheo [17], dirhodium(II) [18], and boron trifluoride [19]. Using a catalyst in the organic synthesis reaction gives significantly higher product yields and a shorter time than without a catalyst [20].…”

Synthesis of Blue Emissive Quaternary 9,9-Disubstituted N-Methyl-7-azaindole-Appended (Phenylethynyl)-fluorene Derivatives

“…The propargylic alcohols and their derivatives are extremely useful synthons for organic synthesis . Various propargylic alcohols are highly reactive with Lewis acid reagents and undergo nucleophilic substitution reactions with various nucleophiles to produce diverse and functionalized products. − The synthesis of 3,4-dihydrocyclopenta­[ b ]­indole and 1,4-dihydrocyclopenta­[ b ]­indole and propargylic alcohol in the presence of different catalysts are known . We have been working on the chemistry of fluorene propargylic alcohol and diverse nucleophiles under Lewis acid conditions .…”

BF3·OEt2 catalyzed synthesis of functionalized 9-fluorene-9-ylidene appended quinazolin-4-ones

“…Several groups are working on the synthesis of diverse heterocyclic compounds using propargylic alcohols as the key starting material and α,β-unsaturated hydrazones, 11 aziridines, 12 isatin imines, 13 sulfonamides 14 azides, 15 enaminones, 16 and indole. The synthesis of dihydroquinolines and indoles via arylamines and propargylic alcohol catalyzed by FeCl 3 ·6H 2 O is known and while using fluorene propargylic alcohol, indole was the sole product.…”