![trans-10,11-dibromo-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-one](/Databaselist/images/loading.webp)
2222-33-5Relevant academic research and scientific papers
Photochemistry of trans-10,11-Dibromodibenzosuberone: A Near-UV Photoacid Generator
Gannon, T.,McGimpsey, W. G.
, p. 913 - 916 (1993)
Pulsed laser irradiation of trans-10,11-dibromodibenzosuberone, I, in room-temperature benzene and acetonitrile solutions resulted in efficient debromination to yield dibenzosuberone, II.In benzene, the transient absorption due to the bromine atom (Br.)-benzene ?-complex was observed, while in acetonitrile with added Br- the transient absorption due to Br2.- was detected.In both cases, transient production was instantaneous, indicating that Br. is a primary photoproduct.Transient actinometric experiments using the benzophenone triplet state as a standard and Br2.- as the Br. probe allowed the determination of the quantum yield for Br. production, Φ = 2.4 +/- 0.6.In acetonitrile, in the presence of the H-atom donor, 2-propanol, Br.-Br. recombination to give Br2 competes with H-atom abstraction to yield the acid HBr.Under high-intensity laser irradiation, recombination and H-atom abstraction are competitive, while under low flux laser or UV lamp irradiation, H-atom abstraction is very efficient.In the presence of 1-3 M 2-propanol, acid formation was found to be nearly quantitative.
Nitrosoarene-Catalyzed HFIP-Assisted Transformation of Arylmethyl Halides to Aromatic Carbonyls under Aerobic Conditions
Pradhan, Suman,Sharma, Vishali,Chatterjee, Indranil
supporting information, p. 6148 - 6152 (2021/08/03)
A rare metal-free nucleophilic nitrosoarene catalysis accompanied by highly hydrogen-bond-donor (HBD) solvent, 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), organocatalytically converts arylmethyl halides to aromatic carbonyls. This protocol offers an effective means to access a diverse array of aromatic carbonyls with good chemoselectivity under mild reaction conditions. The activation of arylmethyl halides by HFIP to generate stable carbocation and autoxidation of in situ generated hydroxylamine to nitrosoarene in the presence of atmospheric O2 are the keys to success.
Visible light mediated selective oxidation of alcohols and oxidative dehydrogenation of N-heterocycles using scalable and reusable La-doped NiWO4nanoparticles
Abinaya, R.,Balasubramaniam, K. K.,Baskar, B.,Divya, P.,Mani Rahulan, K.,Rahman, Abdul,Sridhar, R.,Srinath, S.
, p. 5990 - 6007 (2021/08/24)
Visible light-mediated selective and efficient oxidation of various primary/secondary benzyl alcohols to aldehydes/ketones and oxidative dehydrogenation (ODH) of partially saturated heterocycles using a scalable and reusable heterogeneous photoredox catalyst in aqueous medium are described. A systematic study led to a selective synthesis of aldehydes under an argon atmosphere while the ODH of partially saturated heterocycles under an oxygen atmosphere resulted in very good to excellent yields. The methodology is atom economical and exhibits excellent tolerance towards various functional groups, and broad substrate scope. Furthermore, a one-pot procedure was developed for the sequential oxidation of benzyl alcohols and heteroaryl carbinols followed by the Pictet-Spengler cyclization and then aromatization to obtain the β-carbolines in high isolated yields. This methodology was found to be suitable for scale up and reusability. To the best of our knowledge, this is the first report on the oxidation of structurally diverse aryl carbinols and ODH of partially saturated N-heterocycles using a recyclable and heterogeneous photoredox catalyst under environmentally friendly conditions.
Substituted 9-Anthraldehydes from Dibenzocycloheptanol Epoxides via Acid-Catalyzed Epoxide Opening/Semipinacol Rearrangement
Phumjan, Tanawat,Songthammawat, Poramate,Jongcharoenkamol, Jira,Batsomboon, Paratchata,Ruchirawat, Somsak,Ploypradith, Poonsakdi
, p. 13322 - 13349 (2021/09/13)
Starting from benzaldehyde derivatives, the corresponding dibenzocycloheptenol could be prepared in five steps. Under both substrate (secondary vs tertiary alcohol and the substituents on the aromatic ring(s)) and condition control, the subsequent epoxidation and acid-catalyzed epoxide opening/semipinacol rearrangement/aromatization afforded the corresponding 9-anthraldehydes in good yields, up to 88% over two steps. The presence of the electron-withdrawing group(s) on the aromatic ring(s) suppressed the rate of the epoxidation while the subsequent semipinacol rearrangement step required heating; the presence of the electron-donating group(s), on the other hand, frequently led to the decomposition during the epoxidation. From the mechanistic studies, the semipinacol rearrangement of the epoxide could precede the ionization at the bisbenzylic position, yielding the aldehyde intermediate. The ensuing dehydrative aromatization led to the formation of 9-anthraldehyde. Conversely, nucleophilic addition to the aldehyde and dehydrative aromatization with concomitant loss of formic acid led to anthracene.
BROMINE FREE PREPARATION OF 5H-DIBENZO [A,D] CYCLOHEPTEN-5-ONE
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Page/Page column 6, (2020/03/23)
The invention relates to a convenient procedure for the preparation of 5H- Dibenzo[a,d] cyclohepten-5-one in high yield an purity from 10,11-Dihydro-5H-dibenzo[a,d]cyclohepten-5-one. The procedure is not only convenient to be adopted on an industrial scale but also safe and environment friendly.
Rapid and efficient debromination of vic-dibromides with VCl3/indium system
Woo Yoo, Byung,Yeon Park, Jee,Jong Shin, Hyo
, p. 275 - 278 (2018/08/21)
The VCl3/In system was found to be a new protocol for debromination of a variety of vic-dibromides to the corresponding alkenes in high yields with short reaction times under mild conditions. This new methodology is highly chemose-lective, tolerating several functional groups such as chloro, bromo, fluoro, keto, ester, carboxyl, and methoxy groups.
CO2-Catalyzed oxidation of benzylic and allylic alcohols with DMSO
Riemer, Daniel,Mandaviya, Bhavdip,Schilling, Waldemar,G?tz, Anne Charlotte,Kühl, Torben,Finger, Markus,Das, Shoubhik
, p. 3030 - 3034 (2018/04/14)
CO2-catalyzed transition-metal-free oxidation of alcohols has been achieved. Earlier, several methodologies have been explored for alcohol oxidations based on transition-metal catalysts. However, owing to the cheaper price, easy separation and nontoxicity, transition-metal-free systems are in high demand to the pharmaceutical industries. For this reason, various primary and secondary alcohols have been selectively oxidized to the corresponding carbonyl compounds using CO2 as a catalyst in the presence of different functional groups such as nitrile, nitro, aldehyde, ester, halogen, ether, and so on. At the end, transition-metal-free syntheses of pharmaceuticals have also been achieved. Finally, the role of CO2 has been investigated in detail, and the mechanism is proposed on the basis of experiments and DFT calculations.
Metal-free oxidation of secondary benzylic alcohols using aqueous TBHP
Wu, Jianglong,Liu, Yan,Ma, Xiaowei,Liu, Ping,Gu, Chengzhi,Dai, Bin
supporting information, p. 1747 - 1758 (2016/10/30)
We report a simple, yet efficient metal-free oxidation of secondary benzylic alcohols in the presence of t-butyl hydroperoxide (70% TBHP) with high yields of up to 98%. This type of reaction can be carried out using a wide variety of substrates, requires no other organic solvent, and proves to be tolerant toward a variety of different functional groups.
Activation of DMSO for Swern-type oxidation by 1,1-dichlorocycloheptatriene
Nguyen, Thanh Vinh,Hall, Michael
supporting information, p. 6895 - 6898 (2015/01/09)
A new dimethylsulfoxide activation method employing 1,1-dichlorocycloheptatriene has been developed for a mild Swern-type oxidation of a variety of alcohols. The carbonyl products can be obtained in good to excellent yields from this operationally simple and efficient method. This work is the first report of dimethylsulfoxide activation by a simple chlorinated hydrocarbon reagent, which has the unique ability of equilibrating to its reactive aromatic cationic form.
Photocatalytic dehalogenation of vicinal dibromo compounds utilizing sexithiophene and visible-light irradiation
McTiernan, Christopher D.,Pitre, Spencer P.,Scaiano, Juan C.
, p. 4034 - 4039 (2015/02/19)
The reductive dehalogenation of a variety of vicinal-dibromide compounds has been accomplished through the use of α-sexithiophene as an organophotocatalyst. This photocatalytic system brings about the desired transformations in good yields, using low catalyst loadings and short reaction times. To help shed light on the efficiency of this process, we have studied the kinetics of the key mechanistic steps utilizing a combination of steady-state/time-resolved fluorescence and laser flash photolysis techniques.
