Additive-assisted regioselective 1,3-dipolar cycloaddition of azomethine ylides with benzylideneacetone

• Chuqin Peng,
• Jiwei Ren,
• Jun-An Xiao,
• Honggang Zhang,
• Hua Yang and
• Yiming Luo

Beilstein J. Org. Chem. 2014, 10, 352–360, doi:10.3762/bjoc.10.33

• prepare a series of novel spiropyrrolidine-oxindoles – 4′-acetyl-3′,5′-diarylspiro[indoline-3,2′-pyrrolidin]-2-ones and 3′-acetyl-4′,5′-diarylspiro[indoline-3,2′-pyrrolidine]-2-ones in good yields of up to 94% and with good regioselectivities. Regioselectivities are reversible by the addition of water or

• ′-diarylspiro(indoline-3,2′-pyrrolidin)-2-one was formed when using chalcone or dienone as dipolarophiles [20][31]. Presumably, this might be attributed to the electronic and steric effects of the acetyl group. Therefore, reaction conditions including various solvents and additives (Table 1, entries 2–9) were

Computational study of the rate constants and free energies of intramolecular radical addition to substituted anilines

• Andreas Gansäuer,
• Meriam Seddiqzai,
• Tobias Dahmen,
• Rebecca Sure and
• Stefan Grimme

Beilstein J. Org. Chem. 2013, 9, 1620–1629, doi:10.3762/bjoc.9.185

• substituted anilines that constitutes the C–C bond forming event of indoline synthesis via homolytic substitution with computational methods. The results are of general interest for the understanding of radical addition to electron rich arenes and should be helpful in the design of novel radical reactions

Organocatalytic asymmetric selenofunctionalization of tryptamine for the synthesis of hexahydropyrrolo[2,3-b]indole derivatives

• Qiang Wei,
• Ya-Yi Wang,
• Yu-Liu Du and
• Liu-Zhu Gong

Beilstein J. Org. Chem. 2013, 9, 1559–1564, doi:10.3762/bjoc.9.177

• . Finally, we demonstrate the synthetic application of this reaction in the construction of the 3a-(phenylselenyl)bispyrrolidino[2,3-b]indoline core structure (Scheme 2). Under the optimized reaction conditions, the enantioselective substitution reaction gave 4a in 78% yield and 86% ee. However, when the

• chiral precursor of the (+)-alline. Catalysts and seleno reagents evaluated in this study. Generality for substitution at the indoline moiety. The reaction was performed in 0.1 mmol scale in DCE (1 mL) with 5 Å MS (100 mg) in 0 °C and the ratio of 2/1 is 3:1. The reaction was performed for 1–3 days. The

A construction of 4,4-spirocyclic γ-lactams by tandem radical cyclization with carbon monoxide

• Mitsuhiro Ueda,
• Yoshitaka Uenoyama,
• Nozomi Terasoma,
• Shoko Doi,
• Shoji Kobayashi,
• Ilhyong Ryu and
• John A. Murphy

Beilstein J. Org. Chem. 2013, 9, 1340–1345, doi:10.3762/bjoc.9.151

• azides with CO was achieved. The reaction of iodoaryl allyl azides, TTMSS and AIBN under CO pressure (80 atm) in THF at 80 °C gave the desired 4,4-spirocyclic indoline, benzofuran, and oxindole γ-lactams in moderate to good yields. Keywords: 4,4-spirocyclic indol γ-lactams; carbon monoxide; free radical

• reaction of 1a with Bu3SnH (2.0 equiv) and AIBN (2,2’- azobisisobutyronitrile, 0.3 equiv) was carried out under CO pressure (80 atm) in THF (0.02 M) at 80 °C for 12 h, which gave the desired 4,4-spirocyclic indoline γ-lactam 2a in 48% yield (Scheme 4). We found that the modest improvement in the yield of

• indoline γ-lactam 2f and a (TMS)3Si radical, thus creating a radical chain. On the other hand, the unusual formation of THF-incorporating lactam 3 from 1g may be rationalized by the consecutive 6-endo cyclization of E and β-elimination of an azidyl radical from the resulting F, to give 2-methylene lactam G

Facile synthesis of functionalized spiro[indoline-3,2'-oxiran]-2-ones by Darzens reaction

• Qin Fu and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 918–924, doi:10.3762/bjoc.9.105

• Qin Fu Chao-Guo Yan College of Chemistry & Chemical Engineering, Yangzhou University, Yangzhou 225002, China 10.3762/bjoc.9.105 Abstract A series of functionalized spiro[indoline-3,2'-oxiran]-2-ones was efficiently synthesized by Darzens reaction of phenacyl bromides with isatins both with N

• phenacyl bromides and report the facile synthesis of versatile spiro[indoline-3,2'-oxiran]-2-ones. Results and Discussion In recent years we have found that pyridinium salts react with versatile reactive methylene compounds to give different kinds of products, including functionalized cyclopropanes, 2,3

• . Isatins, phenacyl bromide and other reagents are commercial reagents and were used as received. Solvents were purified by standard techniques. All reactions were monitored by TLC. Typical procedure for the preparation of spiro[indoline-3,2'-oxiran]-2-ones 3a–h: A mixture of isatin (1.0 mmol), phenacyl

Synthesis of functionalized spiro[indoline-3,4’-pyridines] and spiro[indoline-3,4’-pyridinones] via one-pot four-component reactions

• Li-Juan Zhang,
• Qun Wu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 846–851, doi:10.3762/bjoc.9.97

• malononitrile afforded the functionalized spiro[indoline-3,4’-pyridine] derivatives in good yields. Similar reactions with ethyl cyanoacetate successfully afforded the functionalized spiro[indoline-3,4’-pyridines] and spiro[indoline-3,4’-pyridinones] as the main products according to the structures of the

• [12][13][14][15][16][17][18][19][20][21][22][23]. Recently, Perumal and we have both developed an efficient synthetic procedure for functionalized spiro[indoline-3,4’-pyridines] by domino reactions of in situ generated β-enamino esters, isatin and malononitrile with triethylamine as the base catalyst

• reactions of arylamines, methyl propiolate, aromatic aldehydes and malononitrile (ethyl cyanoacetate) and successfully developed a facile synthetic procedure for functionalized spiro[indoline-3,4’-pyridines] and spiro[indoline-3,4’-pyridinones]. Results and Discussion The efficient formation of

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

• Perkin-Elmer AX-1 spectrophotometer in KBr disc and are reported in wave number (cm−1). ESIMS spectrometers were used for mass spectra analysis. Synthesis of 1-phenyl-3-(methylthio)-5H-dibenzo[d,f][1,3]diazepin-6(7H)-one (5) A mixture of indoline-2-one (4, 1.1 mmol) and 2-pyranone (3, 1.0 mmol) and t

Intramolecular carbonickelation of alkenes

• Rudy Lhermet,
• Muriel Durandetti and
• Jacques Maddaluno

Beilstein J. Org. Chem. 2013, 9, 710–716, doi:10.3762/bjoc.9.81

• outcome of the cyclization differs. While allylic ethers are relatively poor substrates that undergo a side elimination and need an intracyclic double bond to proceed, allylic amines react well and afford indoline and indole derivatives. Finally, the synthesis of the trinuclear ACE core of a morphine-like

• pathway affording indoline 3c is slightly increased, and a (2c + 2c’)/3c ratio of 62/38 is observed (Table 1, entry 4). In conclusion to the first part of this study, the formation and cyclization of arylnickel intermediates 1-Ni is observed in all cases. Afterward, the stability of the exo-methylene

• , with a lesser amount of indoline 3 being obtained above when this protecting group was employed. The carbonickelation protocol was applied to the cyclization of crotyl derivatives 5 (Scheme 3). When applied to ether 5a, as expected, the substitution of the allyl moiety at the terminal position by a

Some aspects of radical chemistry in the assembly of complex molecular architectures

• Béatrice Quiclet-Sire and
• Samir Z. Zard

Beilstein J. Org. Chem. 2013, 9, 557–576, doi:10.3762/bjoc.9.61

• –cyclisation leading to indoline 97 with an intramolecular Friedel–Crafts reaction to afford a tricyclic derivative 98 substituted by a trifluoromethyl group [44]. The second exploits the presence of both a protected primary amine and an easily substitutable chlorine on the pyrimidine ring in 99a,b to afford

• and cyclisation of the latter into indoline 109 [47]. Diverse otherwise inaccessible chloroketones become readily available. Haloketones in general are ideal precursors for the synthesis of numerous heteroaromatic derivatives. For example, Hantzsch condensation of indoline 109 with thionicotinamide

• . Synthesis of bicyclic cyclobutane motifs. Construction of the CD rings of steroids. Rapid assembly of polyquinanes. Formation of a polycyclic structure via an allene intermediate. A polycyclic structure via the alkylative Birch reduction. Synthesis of polycyclic pyrimidines and indoline structures

Inter- and intramolecular enantioselective carbolithiation reactions

• Asier Gómez-SanJuan,
• Nuria Sotomayor and
• Esther Lete

Beilstein J. Org. Chem. 2013, 9, 313–322, doi:10.3762/bjoc.9.36

• L8, leading to the indoline of opposite configuration. Unfortunately, this diamine is not commercially available, and its synthesis requires resolution. More recently, O’Brien [48] has reported that (+)-sparteine surrogate L2 gave a similar degree of enantioselectivity and indoline (S)-38a of 85:15

Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

• Yan Sun,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 8–14, doi:10.3762/bjoc.9.2

• three-component reaction of arylamine, isatin and cyclopentane-1,3-dione. Results and Discussion Recently we found that the four-component reactions of arylamine, acetylenedicarboxylate, isatin and dimedone in acetic acid resulted in the novel functionalized tetrahydrospiro[indoline-3,2’-quinoline

Organocatalytic C–H activation reactions

• Subhas Chandra Pan

Beilstein J. Org. Chem. 2012, 8, 1374–1384, doi:10.3762/bjoc.8.159

• as the substrate, and the N-alkyl-indoline product 10 was obtained in good yields (70–82%) mainly by the method of the Pan group (Scheme 7). In this case, another molecule of indoline acts as the hydride donor and is converted to indole. Both Tunge and Pan suggested redox isomerization in the

• azomethine ylide intermediates in the Tunge pyrrole formation and in the formation of N-alkylindoles from indoline [19]. These reactions are considered C–H activation reactions, as during the azomethine ylide formation, the C–H bond that is cleaved is not activated by electron-withdrawing (such as ester

Recent developments in gold-catalyzed cycloaddition reactions

• Fernando López and
• José L. Mascareñas

Beilstein J. Org. Chem. 2011, 7, 1075–1094, doi:10.3762/bjoc.7.124

• , when PtCl2 (under an atmosphere of CO) is used, the major products are 2,3-indoline-fused cyclopentenes 44, which arise from a formal (3 + 2) cycloaddition (lower arrow) [86]. Thus, the appropriate choice of a Pt or Au catalyst determines whether the allenyl intermediate 42 participates as a 2C- or as

Mitomycins syntheses: a recent update

• Jean-Christophe Andrez

Beilstein J. Org. Chem. 2009, 5, No. 33, doi:10.3762/bjoc.5.33

• the p-quinone are called mitosanes or mitosenes depending whether they are at the oxidation state of an indoline (Y1 or Y2 = H) or an indole (Y1 = Y2 = C=C). Compounds bearing an aziridine at C1 and C2 are described specifically as aziridinomitosanes and aziridinomitosenes respectively. Compounds

• reagent, N-phenylselenophthalimide (N-PSP) [83][84]. The attack of this reagent upon the double bond led to indoline 81 which underwent a second alkylation to generate the complete pyrroloindole system 82. It is noteworthy that the cyclization reaction was completely stereospecific. Indeed, one could

• argue that the addition of N-PSP to the olefin 80 to form a selenonium ion is reversible and that the attack of the nitrogen is favored when the two large groups emerge trans relative to the indoline ring. Treatment with m-CPBA then created the double bond which was later fashioned into aziridine 84

Reduction of arenediazonium salts by tetrakis(dimethylamino)ethylene (TDAE): Efficient formation of products derived from aryl radicals

• Mohan Mahesh,
• John A. Murphy,
• Franck LeStrat and
• Hans Peter Wessel

Beilstein J. Org. Chem. 2009, 5, No. 1, doi:10.3762/bjoc.5.1

• : cyclization; electron transfer; indole; indoline; radical; Introduction Arenediazonium salts have long proved useful as sources of aryl radicals in many reactions featuring carbon-carbon (e.g., Meerwein [1], Pschorr [2][3], Gomberg [3] reactions) and carbon-heteroatom bond (e.g., Sandmeyer [4]) formation

• vinblastine (58a) and vincristine (58b) contain such a system. Aryl C-C bond formation As a final extension of this methodology, we probed the feasibility of this methodology in aryl-aryl C-C bond formation reactions. Accordingly, the diazonium salt 62 was prepared from indoline (59), and treated with one

• translocation) by the aryl radical 67 from the carbon atom in the α-position to the nitrogen atom of the indoline nucleus within the same molecule. The indolinyl radical 71 might follow pathway A and undergo radical fragmentation to the intermediate 75 which would eventually tautomerise to indole (63). The