5324-00-5Relevant academic research and scientific papers
The Synthesis of Benzofulvenes through Palladium-Catalyzed Sequential Three-Component Reactions
Zhou, Bo,Wu, Zhuo,Qi, Weixin,Sun, Xueliang,Zhang, Yanghui
, p. 4480 - 4484 (2018/10/31)
An approach for the synthesis of benzofulvenes has been developed through palladium-catalyzed sequential three-component reactions. The reactions likely involve C,C-palladacycles as the key intermediates. The palladacycles are generated through cascade reactions of aryl halides and alkynes, and then reacted with CH2Br2 to form benzofulvenes as the final products. (Figure presented.).
Selective Divergent Synthesis of Indanols, Indanones, and Indenes via Acid-Mediated Cyclization of (Z)- and (E)-(2-Stilbenyl)methanols and Its Application for the Synthesis of Paucifloral F Derivatives
Jongcharoenkamol, Jira,Chuathong, Patsapon,Amako, Yuka,Kono, Masato,Poonswat, Kasam,Ruchirawat, Somsak,Ploypradith, Poonsakdi
, p. 13184 - 13210 (2018/11/02)
Starting from bromo/iodobenzaldehyde derivatives, the corresponding (Z)- and (E)-(2-stilbenyl)methanols could be prepared in 2-5 steps via Pd-catalyzed cross-coupling reactions (Sonogashira and Heck reactions) followed by aryllithium/aryl Grignard addition. For the (E)-stilbenes, subsequent acid-mediated cyclization using p-TsOH immobilized on silica (PTS-Si) at low temperatures furnished the 2,3-trans-1-indanols with complete stereocontrol at the C2-C3. Further oxidization of the alcohol provided the indanones, which are structurally related to the natural product paucifloral F. At higher temperatures, 1,2- and 2,3-disubstituted indenes could be selectively prepared in good to excellent yields. On the other hand, the (Z)-stilbenes, under similar conditions (PTS-Si), did not give the indanols; only the 1,2-disubstituted indenes could be obtained. To gain further insights into the stereochemistry at C2-C3 for the (Z)-stilbenes, hydride or azide was employed as a nucleophile; the corresponding indane products were obtained with the cis stereochemistry at the C2-C3. Thus, the (Z)- or (E)-olefin geometry of the substrate directed the stereoselective indanyl cyclization to furnish the cis or trans at the C2-C3 ring junction, respectively, while reaction conditions controlled the selectivity of the product types.
Intramolecular addition of triarylmethanes to alkynes promoted by KOtBu/DMF: A synthetic approach to indene derivatives
Chen, Yan-Yan,Chen, Zhen-Yu,Zhang, Niu-Niu,Chen, Jia-Hua,Zhang, Xue-Jing,Yan, Ming
, p. 599 - 606 (2016/02/19)
A method for the intramolecular addition of triarylmethanes to alkynes has been developed. The reaction was efficiently promoted by KOtBu/DMF without any transition-metal catalyst. A variety of indene derivatives were prepared in moderate to good yields. A cascade cyclization of 2-alkyl-substituted substrates at elevated reaction temperature gave bicyclic indene derivatives. The reaction is proposed to proceed through the generation of a triphenylmethyl radical. Indene derivatives were prepared by the intramolecular addition of triarylmethanes to alkynes promoted by KOtBu/DMF. A cascade cyclization of 2-alkyl-substituted substrates at elevated reaction temperature gave bicyclic indene derivatives. A free-radical reaction mechanism is proposed.
Palladium-catalyzed annulation of alkynes with ortho -halide-containing benzyl alcohols in aqueous medium
Feng, Jie,Lu, Guoping,Lv, Meifang,Cai, Chun
, p. 10561 - 10567 (2015/02/19)
The Pd-catalyzed annulations of ortho-halide-containing benzyl alcohols with alkynes for the synthesis of indenones were achieved in aqueous Triton X-100 micelles with good yields and wide substrate scopes. Moreover, the indenones obtained in this procedure can be further functionalized to form some more synthetic useful derivatives via an environmental-friendly way.
Synthesis of substituted 2-arylindanes from e -(2-stilbenyl)methanols via lewis acid-mediated cyclization and nucleophililc transfer from trialkylsilyl reagents
Sarnpitak, Pakornwit,Trongchit, Kanokrat,Kostenko, Yulia,Sathalalai, Supaporn,Gleeson, M. Paul,Ruchirawat, Somsak,Ploypradith, Poonsakdi
, p. 8281 - 8296 (2013/09/24)
A preparative method for the synthesis of functionalized 2-arylindanes has been developed via the Lewis acid-mediated ring closure of stilbenyl methanols followed by nucleophilic transfer from trialkylsilyl reagents. The reactions gave the corresponding p
Synthesis of 2-bromo-1-aryl-1H-indenes via a Ag(I) promoted domino 2π-electrocyclic ring-opening/4π-electrocyclization reaction of 1,2-diaryl substituted gem-dibromocyclopropanes
Rosocha, Gregory,Batey, Robert A.
, p. 8758 - 8768 (2013/09/23)
2-Bromo-1-aryl substituted indenes can be synthesized from 1,2-diaryl substituted gem-dibromocyclopropanes via a domino reaction sequence. The cascade reaction involves silver(I) promoted ionization and 2π-disrotatory electrocyclic ring-opening, followed by a 4π-conrotatory electrocyclic ring closing reaction of the allylic carbocation intermediate. Reaction conditions utilize silver tetrafluoroborate (AgBF4) in dichloroethane at 65 C. Selectivity effects for the electrocyclization were also studied. The 2-bromoindenes can be further functionalized using cross-coupling reactions, such as the Suzuki-Miyaura protocol. The alkene π-bond of the indenes can also be isomerized to give the thermodynamically more stable 2-bromo-3-aryl-1H-indene isomers using triethylamine in dichloromethane at room temperature.
1,2,3,4-Tetrasubstituted cyclopentadienes and their applications for metallocenes: Efficient synthesis through zirconocene- and CuCl-mediated intermolecular coupling of two alkynes and one diiodomethane
Geng, Weizhi,Wang, Chao,Guang, Jie,Hao, Wei,Zhang, Wen-Xiong,Xi, Zhenfeng
, p. 8657 - 8664 (2013/07/26)
1,2,3,4-Tetrasubstituted cyclopentadienes and indene derivatives with identical or different substituents were obtained in good to excellent isolated yields through a zirconocene- and CuCl-mediated intermolecular coupling process. This synthetic procedure involved three organic partners, including one CH 2I2, and two different or identical alkynes. Two alkynes or one diyne undergo Cp2ZrII-mediated (Cp= η5-C5H5) pair-selective reductive coupling to afford the corresponding zirconacyclopentadiene derivatives, which react, in the presence of CuCl and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1 H)-pyrimidinone (DMPU), with CH2I2 through intermolecular followed by intramolecular coupling to afford the cyclopentadiene derivatives. An application of the prepared tetrasubstituted cyclopentadiene derivatives was demonstrated by the facile synthesis of the corresponding zirconocene complexes [(4RCp)2ZrCl2] and [(4RCp) 2ZrR′2] (R′=Me, Et, or nBu). The unique 1,2,3,4-tetrasubstituted cyclopentadiene ligands and the corresponding metallocenes are expected to have further applications in organometallic chemistry and organic synthesis. Ringing in the changes: A one-pot synthesis of 1,2,3,4-tetrasubstituted cyclopentadienes by zirconocene- and CuCl-mediated intermolecular coupling of two alkynes and diiodomethane (see scheme; Cp=η5-C5H5; DMPU=1,3-dimethyl-3,4,5,6- tetrahydro-2(1 H)-pyrimidinone) gave products that were successfully applied for the synthesis of the corresponding zirconocene derivatives. Copyright
Niobium-catalyzed activation of CF3 group on alkene: Synthesis of substituted indenes
Fuchibe, Kohei,Atobe, Kohei,Fujita, Yukari,Mori, Keiji,Akiyama, Takahiko
supporting information; experimental part, p. 867 - 869 (2011/01/07)
A CF3 group attached to an alkene functionality was activated by a zero-valent niobium catalyst to generate niobium alkenylcarbenoid species. The niobium carbenoid species then underwent insertion to an internal aromatic C-H σ bond to give inde
Novel alkylidenating agents of iron(III) derivatives by base-mediated α,μ-dehydrohalogenation and their chemical trapping by cycloaddition
Eisch, John J.,Sohn, Jane U.,Rabinowitz, Edon J.
experimental part, p. 2971 - 2977 (2010/08/20)
Studies of the reactions between group 4 metal, chlorides (M = Ti, Zr, Hf) and methyllithium at -78 °C in toluene can lead to methylidene-metal complexes, H2C=MCl2, by a sequence of monomethylation, α-carbon lithiation and α,μ-elimination of LiCl. Here study of the preparation of alkylidene derivatives of iron was attempted by the interaction of FeCl3 with n-butyllithium in various ratios at -78 °C. The presence of any resulting butylidene-iron(III) derivative, nPrCH=FeE (E = Cl, nBu), was probed by adding chemical trapping agents, such as diphenylacetylene, benzonitrile, methyl benzoate and benzophenone. In each experiment the hydrolyzed products were consistent with a cycloaddition reaction of nPrCH=FeE with the trapping agent. The products from, di-phenylacetylene and from, benzonitrile with D2O workup are uniquely in accord with such a carbene precursor. A 3:1 ratio of nBuLi/FeCl3 gave the optimal yield of nPrCH=FenBu, ca. 80%, from, the MBu2FeCl precursor. When a 3:1. reaction mixture was simply brought to 25 °C and hydrolyzed, the purple alkylidene-iron complex decomposed completely to iron metal. A study of a 3:1 interaction of PhCH2MgCl and FeCl3 under similar conditions and trapping with diphenylacetylene provided evidence for the formation of PhCH=FeCH2Ph in ca. 40%. These results support; the hope that alkylidene-iron(III) analogs of the Grubbs reagents may be accessible by this process.
Palladium-catalyzed double cross-coupling reaction of vic-diborylalkenes and -arenes with vic-bromo(bromomethyl)arenes
Shimizu, Masaki,Tomioka, Yosuke,Nagao, Ikuhiro,Hiyama, Tamejiro
scheme or table, p. 3147 - 3150 (2010/03/24)
Efficient annulation of vic-diborylalkenes and -arenes with vic-bromo(bromomethyl)arenes has been achieved, using Pd(PPh3) 4 as a catalyst in the presence of Cs2CO3 and water in THF at 60°C, giving rise to the c
