Copper-catalyzed multicomponent reactions for the efficient synthesis of diverse spirotetrahydrocarbazoles

• Shao-Cong Zhan,
• Ren-Jie Fang,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 796–808, doi:10.3762/bjoc.18.80

• -dimethylbarbituric acids or 2-arylidene-1,3-cycloketones efficiently afforded diverse cyclic spirotetrahydrocarbazoles in good yields and with high diastereoselectivity (reaction 3 in Scheme 1). Results and Discussion Initially, (E)-1-benzyl-3-(2-oxo-2-phenylethylidene)indolin-2-one, benzaldehyde, and 2-methylindole

• = 1:5–1:8) as eluent to give pure 1a–j and 1a’–j’. 2-Benzoyl-1'-benzyl-4-phenyl-1,2,4,9-tetrahydrospiro[carbazole-3,3'-indolin]-2'-one (1a): Purple solid, 61%, mp 182–185 °C; 1H NMR (400 MHz, CDCl3) δ 8.23 (s, 1H, NH), 7.89 (d, J = 7.2 Hz, 1H, ArH), 7.54 (t, J = 7.2 Hz, 1H, ArH), 7.43–7.39 (m, 3H, ArH

Tri(n-butyl)phosphine-promoted domino reaction for the efficient construction of spiro[cyclohexane-1,3'-indolines] and spiro[indoline-3,2'-furan-3',3''-indolines]

• Hui Zheng,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 669–679, doi:10.3762/bjoc.18.68

• of readily available 1,3-dipolarophile, 3-phenacylidenoxindole, was also tested in the reaction. However, it was found that the C=C bond in 3-phenacylidenoxindole was directly reduced to give the corresponding saturated 3-(2-oxo-2-phenylethyl)indolin-2-one. A similar reduction reaction of 3

Tosylhydrazine-promoted self-conjugate reduction–Michael/aldol reaction of 3-phenacylideneoxindoles towards dispirocyclopentanebisoxindole derivatives

• Sayan Pramanik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 469–478, doi:10.3762/bjoc.18.49

• heterocyclic frameworks [31][32]. During our preliminary investigations as shown in Table 1, we commenced our study by reacting two equivalents of (E)-3-(2-(4-chlorophenyl)-2-oxoethylidene)indolin-2-one (1a) under reflux conditions with one equivalent of tosylhydrazine (2) as hydrogen source in ethanolic

• proposed mechanism at first we performed an HRMS analysis of the crude reaction mixture before completion of the reaction, starting with (E)-1-methyl-3-(2-oxo-2-phenylethylidene)indolin-2-one (1j) and tosylhydrazine under the optimized reaction conditions. To our delight, the HRMS spectrum clearly shows

• -phenylethylidene)indolin-2-one (1j) in acetonitrile with Et3N catalyst under refluxing conditions, and isolated the corresponding saturated ketone 1-methyl-3-(2-oxo-2-phenylethyl)indolin-2-one (4j) in 60% yield, which results from reduction of the double bond of α,β-unsaturated ketone (Scheme 5). The structure of

Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

• -bis(hydroxymethyl)indolin-2-one (51) was reacted first with mesyl chloride and then treated with sodium sulfide to afford 6-bromospiro[indoline-3,3′-thietan]-2-one (53), which was further converted into the target inhibitor candidate 54 [42] (Scheme 12). 2-Methylene-γ-butyrolactone (55) as the initial

A new and convenient synthetic way to 2-substituted thieno[2,3-b]indoles

• Roman A. Irgashev,
• Arseny A. Karmatsky,
• Gennady L. Rusinov and
• Valery N. Charushin

Beilstein J. Org. Chem. 2015, 11, 1000–1007, doi:10.3762/bjoc.11.112

• approach to thieno[2,3-b]indoles, bearing a wide range of aromatic and heteroaromatic substituents at C-2 with various electronic characteristics. Target thieno[2,3-b]indoles have been synthesized from 3-(2-oxo-2-(hetero)arylethylidene)indolin-2-one by treatment of the latter with Lawesson’s reagent

• reflectance attachment (DRA). X-ray diffraction analysis was performed on an automated X-ray diffractometer “Xcalibur E” on standard procedure. General procedure for the synthesis of 3-(2-oxo-2-(hetero)arylethylidene)indolin-2-one 10a−10o The solution of 1-alkylisatin 7 (3 mmol), corresponding methyl ketone 8

• preparation of compounds 10a–d, 10g–k): A drop of hydrochloric acid was added to the suspension of crude adduct 9 in acetic acid (3 mL). The mixture was stirred at 100 °C for 30 min. After cooling the precipitate was filtered, washed with methanol and dried to give indolin-2-one 10 as an orange to dark-red

Novel indolin-2-one-substituted methanofullerenes bearing long n-alkyl chains: synthesis and application in bulk-heterojunction solar cells

• Irina P. Romanova,
• Andrei V. Bogdanov,
• Inessa A. Izdelieva,
• Vasily A. Trukhanov,
• Gulnara R. Shaikhutdinova,
• Dmitry G. Yakhvarov,
• Shamil K. Latypov,
• Vladimir F. Mironov,
• Vladimir A. Dyakov,
• Ilya V. Golovnin,
• Dmitry Yu. Paraschuk and
• Oleg G. Sinyashin

Beilstein J. Org. Chem. 2014, 10, 1121–1128, doi:10.3762/bjoc.10.111

• of long-chain alkyl fragments to the IM nitrogen atom. As a result, the series of novel alkyl-containing indolin-2-one-substituted methanofullerenes (AIMs 2–9) were synthesized. Optical absorption and electrochemical properties of AIMs 1–9 were studied. Bulk heterojunction polymer solar cells based

• )[5,6]fulleren-3-yl)-indolin-2-one (AIM 1) was synthesized according to ref. [7]. Isatins A 2–9 were obtained by known procedures [11][12][13][14]. The general procedure for synthesis of 1-alkyl-3-(3-cyclopropane[1][9](C60-Ih)[5,6]fulleren-3-yl)-indolin-2-one (AIMs 2–9) was as follows: tris(diethylamino

Direct alkenylation of indolin-2-ones by 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles: a novel approach

• Sandeep Kumar,
• Ramendra Pratap,
• Abhinav Kumar,
• Brijesh Kumar,
• Vishnu K. Tandon and
• Vishnu Ji Ram

Beilstein J. Org. Chem. 2013, 9, 809–817, doi:10.3762/bjoc.9.92

• of the weak noncovalent interactions operating in the supramolecular architectures of alkenylated indoline-2-ones and to explain the relative stability of one of the tautomers with respect to the others. Keywords: alkenylation; dibenzo[d,f][1,3]diazepin-6(7H)-one; indolin-2-one; ketene dithioacetal

• powdered KOH in DMF at room temperature as reported earlier [41][42] (Scheme 1). The reaction between indolin-2-one (4) and 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles 3 in the presence of t-BuOK/MeONa in tert-butanol/methanol under reflux resulted in 1-aryl-3-methylthio-5H-dibenzo[d,f][1,3]diazepin

• interaction. Hence, density functional theory (DFT) calculations also indicate that the tautomer 8y is relatively more stable than 8x and 8z (Figure 2). Further, in order to generalize the reaction, attempts were made for the alkenylation of indolin-2-one with 6-aryl-4-sec-amino-2H-pyran-2-one-3-carbonitriles

A thermally-induced, tandem [3,3]-sigmatropic rearrangement/[2 + 2] cycloaddition approach to carbocyclic spirooxindoles

• Kay M. Brummond and
• Joshua M. Osbourn

Beilstein J. Org. Chem. 2010, 6, No. 33, doi:10.3762/bjoc.6.33

• observed, but are likely intermediates of an infrequently encountered thermal [3,3]-sigmatropic rearrangement of a propargylic acetate. Keywords: allene; propargylic acetate; spirooxindole; thermal [2 + 2] cycloaddition; thermal [3,3]-sigmatropic rearrangement; vinylidene indolin-2-one; Introduction

• , the feasibility of this method for the preparation of spirooxindole alkaloids was investigated. The preliminary results of this study are reported herein. Results and Discussion To begin the investigation, the first challenge was the preparation of a functionalized vinylidene indolin-2-one 5 (Figure 2

• -2-one and an alkyne. The cycloaddition reaction occurs selectively with the distal double bond of the allene, is tolerant of a phenyl and trimethylsilyl group on the terminus of the alkyne, and can be used to access bicyclo[4.2.0]octadienes and bicyclo[5.2.0]nonadienes. The allene precursors are not