243-46-9Relevant academic research and scientific papers
Synthesis of Benzo[b]thiophenes through Rhodium-Catalyzed Three-Component Reaction using Elemental Sulfur
Moon, Sanghun,Kato, Moena,Nishii, Yuji,Miura, Masahiro
supporting information, p. 1669 - 1673 (2020/03/23)
A benzo[b]thiophene synthesis by Rh-catalyzed three-component coupling reaction of arylboronic acids, alkynes, and elemental sulfur (S8) is developed. A notable feature of this protocol is that the thienannulation (thiophene annulation) proceeds with high regioselectivity via the sequential alkyne insertion, C?H activation, and then sulfur atom transfer to the metallacycle intermediate. In a similar manner, dibenzothiophenes can be synthesized from the parent biarylboronic acids and S8. (Figure presented.).
A Pd-catalyzed optional approach for the synthesis of dibenzothiophenes
Song, Juan,Wu, Hao,Sun, Wei,Wang, Songjiang,Sun, Haisen,Xiao, Kang,Qian, Yan,Liu, Chao
supporting information, p. 2083 - 2087 (2018/03/26)
A direct and practical approach for the construction of DBTs was developed via a Pd-catalyzed tandem reaction, in which commercially available o-bromo-iodobenzenes combined with benzene thiols or iodobenzenes combined with o-bromo-benzene thiols were applied. These two approaches will provide an alternative for the synthesis of DBT derivatives.
Palladium catalysis based one-pot synthesis method for DBTs (dibenzothiophenes)
-
Paragraph 0033-0038, (2020/05/12)
The invention discloses a palladium catalysis based one-pot synthesis method for DBTs (dibenzothiophenes). An inorganic base is added to an N,N-dimethylacetamide solution, with a palladium catalyst/ligand as a catalysis system, o-bromoiodobenzene derivatives or iodobenzene derivatives and thiophenol derivatives taken as raw materials are subjected to a reaction in nitrogen atmosphere, and DBTs areobtained through separation. The simple, economical and easily available raw materials are taken as substrates, all-position-substituted DBTs are synthesized on the basis of palladium catalyzed cascade reaction, and DBTs have great application prospect in medical synthesis intermediates and organic optoelectronic material science.
Ultrasound assisted Bradsher reaction in aqueous and non-aqueous media: First use of ultrasounds in electrophilic aromatic cyclisation leading to polyacenes
Kowalska, Emilia,Ba?czewski, Piotr
, p. 743 - 753 (2016/07/25)
The present work describes the first use of ultrasounds in the Bradsher cyclisation of activated and non-activated ortho-formyl diarylmethanes. This reaction is also the first example of electrophilic, aromatic cyclisation assisted by ultrasounds which leads to pure polycyclic, fused aromatic hydrocarbons containing 3 and 4 fused rings in excellent yields. The reaction proceeds not only in aqueous but also in non-aqueous media at milder conditions (room temperature) and in much shorter reaction times than in conventional protocols.
Synthesis of annulated arenes and heteroarenes by hydriodic acid and red phosphorus mediated reductive cyclization of 2-(Hetero)aroylbenzoic acids or 3-(Hetero)arylphthalides
Rafiq, Settu Muhamad,Mohanakrishnan, Arasambattu K.
supporting information, p. 362 - 370 (2017/02/10)
Annulated arenes and hetarenes were prepared in good to very good yields by hydriodic acid/red phosphorus mediated reductive cyclization of 3-(hetero)aryl phthalides. The reductive cyclization also proceeded successfully with 2-aroylbenzoic acids and 2-aroylnaphthoic acids.
Palladium(ii)-catalyzed synthesis of dibenzothiophene derivatives via the cleavage of carbon-sulfur and carbon-hydrogen bonds
Tobisu, Mamoru,Masuya, Yoshihiro,Baba, Katsuaki,Chatani, Naoto
, p. 2587 - 2591 (2016/04/05)
A new process has been developed for the palladium(ii)-catalyzed synthesis of dibenzothiophene derivatives via the cleavage of C-H and C-S bonds. In contrast to the existing methods for the synthesis of this scaffold by C-H functionalization, this new catalytic C-H/C-S coupling method does not require the presence of an external stoichiometric oxidant or reactive functionalities such as C-X or S-H, allowing its application to the synthesis of elaborate π-systems. Notably, the product-forming step of this reaction lies in an oxidative addition step rather than a reductive elimination step, making this reaction mechanistically uncommon.
Synthesis of Annulated Anthracenes, Carbazoles, and Thiophenes Involving Bradsher-Type Cyclodehydration or Cyclization-Reductive-Dehydration Reactions
Rafiq, Settu Muhamad,Sivasakthikumaran, Ramakrishnan,Karunakaran, Jayachandran,Mohanakrishnan, Arasambattu K.
, p. 5099 - 5114 (2015/08/18)
A conventional BF3·OEt2-mediated Bradsher-type cyclodehydration of 2-arylmethyl benzaldehydes in CH2Cl2 at room temperature gave polycyclic aromatic and heteroaromatic compounds. Alternatively, these compounds could be synthesized in better yields from 2-arylmethylbenzoic acids by triflic-acid-mediated cyclization followed by reductive dehydration.
Synthesis of dibenzothiophenes by pd-catalyzed dual C-H activation from diaryl sulfides
Che, Rui,Wu, Zhiqing,Li, Zhengkai,Xiang, Haifeng,Zhou, Xiangge
supporting information, p. 7258 - 7261 (2014/06/23)
Palladium-catalyzed dual C-H functionalization of diaryl sulfides to form dibenzothiophenes (DBTs) by oxidative dehydrogenative cyclization is reported. This protocol afforded various DBTs in moderate to good yields with tolerance of a wide variety of substrates. Benzo[1,2-b:4,5-b]bis[b]benzothiophene was successfully synthesized by this method, which was used as an organic semiconductor for field-effect transistors.
Lewis acid/Broensted acid mediated benz-annulation of thiophenes and electron-rich arenes
Rafiq, Settu Muhamad,Sivasakthikumaran, Ramakrishnan,Mohanakrishnan, Arasambattu K.
supporting information, p. 2720 - 2723 (2014/06/09)
A facile preparation of benz-annulated heterocycles were achieved at rt involving a Lewis acid/Broensted acid mediated annulation of heterocycles using 2,5-dimethoxytetrahydrofuran as a four-carbon synthon. The benz-/naphth-annulation was found to be successful with electron-rich arenes as well.
Lewis acid mediated one-pot synthesis of aryl/heteroaryl-fused carbazoles involving a cascade Friedel-Crafts alkylation/electrocyclization/aromatization reaction sequence
Sureshbabu, Radhakrishnan,Saravanan, Velu,Dhayalan, Vasudevan,Mohanakrishnan, Arasambattu K.
, p. 922 - 935 (2011/04/22)
A Lewis-acid-mediated domino reaction of 2/3-(bromomethyl)indoles with arenes/heteroarenes led to the formation of the corresponding annulated carbazoles. This three-step one-pot transformation proceeds by sequential Lewis acid catalysed Friedel-Crafts alkylation, electrocyclization and aromatization reactions. The strategy is highly efficient for the assembly of complex aryl/heteroaryl-fused carbazoles.
