Selective Synthesis of Diverse Spiro-oxindole-fluorene Derivatives via a DABCO-Promoted Annulation Reaction of Bindone and 3-Methyleneoxindoles

Abstract

A DABCO-promoted annulation reaction of bindone ([1,2′-biindenylidene]-1′,3,3′-trione) and 3-methyleneoxindoles showed very interesting molecular diversity under different reaction conditions. The base-promoted annulation reaction of bindone and 3-phenacylideneoxindoles in DCM at room temperature afforded spiro[indeno[1,2-a]fluorene-5,3′-indoline] derivatives in good yields and with high diastereoselectivity. However, the similar reaction of 2-(2-oxoindolin-3-ylidene) acetates resulted in Z/E-isomeric spiro[indeno[1,2-a]fluorene-5,3′-indolines] with diastereomeric ratios of 2:1 to 10:1. On the other hand, the DABCO-promoted annulation reaction of bindone and 3-methyleneoxindoles in acetonitrile at different temperatures selectively gave spiro[benzo[5,6]pentaleno[1,6a-b]naphthalene-7,3′-indoline] derivatives and complex dispiro[indoline-3,6′-[4b,6a]ethanoindeno[1,2-a]fluorene-14′,3″-indolines] in satisfactory yields.

Domino reaction of bindone and 1,3-dipolarophiles for the synthesis of diverse spiro and fused indeno[1,2-a]fluorene-7,12-diones

“…For explaining the mechanism of the above formal [3 + 3] and [4 + 2] cycloaddition reactions, a plausible reaction mechanism was proposed as shown in Scheme 2 according to the known results 11 and present experiments. Firstly, a carbanion ( A ) was formed by deprotonation of bindone in the presence of a base.…”

“…9,10 In recent years, we successfully found that bindone can be easily in situ generated by base catalyzed dimerization and sequentially undergoes an interesting annulation reaction to give diverse indanone-containing polycyclic compounds. 11 In this respect, it has been found that the triethylamine promoted reaction of 1,3-indanedione with 3-arylideneindolin-2-ones in ethanol gave the carbamato-substituted indeno[1,2- a ]fluorenes, in which the reactive bindone was in situ generated to undergo a formal [4 + 2] addition reaction and a further ring-opening process (eqn (1) in Scheme 1). 11 a The base promoted annulation reaction of bindone with 3-phenacylideneoxindoles in DCM at room temperature afforded novel spiro[indeno[1,2- a ]fluorene-5,3′-indoline] derivatives through formal [4 + 2] cycloaddition reaction processes (eqn (2) in Scheme 1).…”

Convenient construction of polycyclic architectures via multicomponent reaction of amino acids, dialkyl but-2-ynedioates and 2-(o-hydroxyarylidene)-1,3-indanediones

“…By using 2-arylidene-1,3-indanediones as key substrates, we have developed a couple of domino multicomponent reactions for providing easy access to diverse novel indanone-containing polycyclic systems. 11–13 Recently, we successfully found that the three-component reaction of alkyl glycinate hydrochloride, dialkyl but-2-ynedioate and 2-arylidene-1,3-indanediones in ethanol resulted in functionalized dihydrospiro[indene-2,3′-pyrrolidines]. 14 In this reaction a new type of azomethine ylide was generated from the reaction of alkyl glycinate and dialkyl but-2-ynedioate, which in turn underwent [3+2] cycloaddition reaction with 2-arylidene-1,3-indanedione.…”

Synthesis of diverse spiro-imidazo pyridine-indene derivatives via acid-promoted annulation reaction of bindone and heterocyclic ketene aminals

“…In 2021, Yan and coworkers have reported a selective synthesis of spiro[benzo[5,6]pentaleno[1,6 a - b ]naphthalene-7,3 ' -indoline] derivatives and complex dispiro[indoline-3,6 ' -[4 b ,6 a ]-ethanoindeno[1,2- a ]fluorene-14 ' ,3 '' -indolines] via a DABCO-promoted annulation reaction of bindone and 3-methyleneoxindoles in acetonitrile at various temperatures for the in optimized yields (Fig. 4 ) 23 .

Figure 2 Condensation of 1,3-indanedione in basic or acidic conditions.

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