17890-56-1Relevant academic research and scientific papers
Solvent-free microwave synthesis of 3-(4-benzo[b]-thiophene-2-carbonyl)-1-piperazinyl-1-benzo[b]thiophen-2-YL-1-propanones. New hetero bis-ligands with potential 5-HT1A serotonergic activity
Pessoa-Mahana, Hernan,Kosche C., Johann,Ron H., Nadia,Recabarren-Gajardo, Gonzalo,Saitz B., Claudio,Araya-Maturana, Ramiro,Pessoa-Mahana, C. David
, p. 1913 - 1929 (2008)
A novel series of 2-benzothiophenealkylpiperazine derivatives 11 (a-d) with potential affinity at 5-HT1A serotonin receptors have been synthesized via solvent-free, microwave-promoted Michael addition of benzo[b]thiophene piperazine derivatives 6(a-c) to substituted benzo[b]thiophen-2-yl propenones 10(b,c).
Chromium-Catalyzed Asymmetric Dearomatization Addition Reactions of Halomethyl Heteroarenes
Tian, Qingshan,Bai, Jing,Chen, Bin,Zhang, Guozhu
, p. 1828 - 1831 (2016)
The first asymmetric dearomatization addition reaction of halomethyl arenes including benzofuran and benzothiophene was enabled by chromium catalysis. A variety of aldehydes served as suitable electrophiles under mild reaction conditions. Molecular complexities are quickly increased in a highly diastereo- and enantioselective manner.
Synthesis of Indole/Benzofuran-Containing Diarylmethanes through Palladium-Catalyzed Reaction of Indolylmethyl or Benzofuranylmethyl Acetates with Boronic Acids
Arcadi, Antonio,Calcaterra, Andrea,Chiarini, Marco,Fabrizi, Giancarlo,Fochetti, Andrea,Goggiamani, Antonella,Iazzetti, Antonia,Marrone, Federico,Marsicano, Vincenzo,Serraiocco, Andrea
supporting information, p. 741 - 753 (2021/11/26)
The palladium-catalyzed synthesis of indole/benzofurancontaining diarylmethanes starting from indolylmethyl or benzofuranylmethyl acetates with boronic acids has been investigated. The success of the reaction is influenced by the choice of precatalyst: with indolylmethyl acetates the reaction works well with [Pd(η3-C3H5)Cl]2/XPhos while with benzofuranylmethyl acetates Pd2(dba)3/XPhos is more efficient. The good to high yields and the simplicity of the experimental procedure make this protocol a versatile synthetic tool for the preparation of 2- and 3-substituted indoles and 2-benzo[b]furans. The methodology can be advantageously extended to the preparation of a key precursor of Zafirlukast.
Nickel-Catalyzed Amination of α-Aryl Methyl Ethers
Patel, Purvish,Rousseaux, Sophie A. L.
, p. 492 - 496 (2020/03/13)
α-Aryl amines are prevalent in pharmaceutically active compounds and natural products. Herein, we describe a Ni-catalyzed protocol for their synthesis from readily available α-aryl ethers. While α-aryl ethers have been used as electrophiles in Ni-catalyzed C-C bond formations, their use in C-heteroatom bond formation is much less prevalent. Preliminary mechanistic insight suggests that oxidative addition is facilitated by an anionic ligand and that reductive elimination is a reversible process.
Combined KOH/BEt3Catalyst for Selective Deaminative Hydroboration of Aromatic Carboxamides for Construction of Luminophores
Li, Jinshan,Wang, Jiali,Yang, Jianguo,Yao, Wubing,Zhong, Aiguo
, p. 8086 - 8090 (2020/11/03)
The selective catalytic C-N bond cleavage of amides into value-added amine products is a desirable but challenging transformation. Molecules containing iminodibenzyl motifs are prevalent in pharmaceutical molecules and functional materials. Here we established a combined KOH/BEt3 catalyst for deaminative hydroboration of acyl-iminodibenzyl derivatives, including nonheterocyclic carboxamides, to the corresponding amines. This novel transition-metal-free methodology was also applied to the construction of Clomipramine and luminophores.
Biocatalytic reduction of α,β-unsaturated carboxylic acids to allylic alcohols
Aleku, Godwin A.,Leys, David,Roberts, George W.
, p. 3927 - 3939 (2020/07/09)
We have developed robust in vivo and in vitro biocatalytic systems that enable reduction of α,β-unsaturated carboxylic acids to allylic alcohols and their saturated analogues. These compounds are prevalent scaffolds in many industrial chemicals and pharmaceuticals. A substrate profiling study of a carboxylic acid reductase (CAR) investigating unexplored substrate space, such as benzo-fused (hetero)aromatic carboxylic acids and α,β-unsaturated carboxylic acids, revealed broad substrate tolerance and provided information on the reactivity patterns of these substrates. E. coli cells expressing a heterologous CAR were employed as a multi-step hydrogenation catalyst to convert a variety of α,β-unsaturated carboxylic acids to the corresponding saturated primary alcohols, affording up to >99percent conversion. This was supported by the broad substrate scope of E. coli endogenous alcohol dehydrogenase (ADH), as well as the unexpected CC bond reducing activity of E. coli cells. In addition, a broad range of benzofused (hetero)aromatic carboxylic acids were converted to the corresponding primary alcohols by the recombinant E. coli cells. An alternative one-pot in vitro two-enzyme system, consisting of CAR and glucose dehydrogenase (GDH), demonstrates promiscuous carbonyl reductase activity of GDH towards a wide range of unsaturated aldehydes. Hence, coupling CAR with a GDH-driven NADP(H) recycling system provides access to a variety of (hetero)aromatic primary alcohols and allylic alcohols from the parent carboxylates, in up to >99percent conversion. To demonstrate the applicability of these systems in preparative synthesis, we performed 100 mg scale biotransformations for the preparation of indole-3-aldehyde and 3-(naphthalen-1-yl)propan-1-ol using the whole-cell system, and cinnamyl alcohol using the in vitro system, affording up to 85percent isolated yield.
Bulky N-Heterocyclic-Carbene-Coordinated Palladium Catalysts for 1,2-Addition of Arylboron Compounds to Carbonyl Compounds
Okuda, Yuta,Nagaoka, Masahiro,Yamamoto, Tetsuya
, p. 6291 - 6300 (2020/11/30)
The synthesis of primary, secondary, and tertiary alcohols by the 1,2-addition of arylboronic acids or boronates to carbonyl compounds, including unactivated ketones, using novel bulky yet flexible N-heterocyclic carbene (NHC)-coordinated 2,6-di(pentan-3-yl)aniline (IPent)-based cyclometallated palladium complexes (CYPs) as catalysts is reported. The PhS-IPent-CYP-catalyzed reactions are efficient at low catalyst loadings (0.02–0.3 mol% Pd), and the exceptional catalytic activity for 1,2-addition is attributed to the steric bulk of the NHC ligand. These reactions can yield a wide range of functionalized benzylic alcohols that are difficult to synthesize by classical protocols using highly active organomagnesium or lithium reagents.
Photocycloaddition of S, S-Dioxo-benzothiophene-2-methanol, Reactivity in the Solid State and in Solution: Mechanistic Studies and Diastereoselective Formation of Cyclobutyl Rings
O'Hara, Chelsea,Yang, Chou-Hsun,Francis, Andrew J.,Newell, Brian S.,Wang, Haobin,Resendiz, Marino J. E.
, p. 9714 - 9725 (2019/08/20)
The formation of cyclobutane rings is a promising strategy in the development of potential drugs and/or synthetic intermediates, typically challenging to obtain due to their constrained nature. In this work, the [2 + 2] photocycloaddition reaction of S,S-dioxobenzothiophene-2-methanol was explored in microcrystalline powders and its outcome was compared to that observed in solution. It was found that the molecular constraints inherited within the crystal lattice provide an optimal environment that leads to photodimer 4 as the major product in ca. 9.6:0.4 diastereomeric ratios with conversions >95%. The photoreaction was analyzed via X-ray, displaying a crystalline-to-amorphous transformation and showing that units of monomer 2 align to generate the corresponding dimer with a syn-head-to-tail regio- and diastereoselectivity. This result contrasted with that obtained in solution, where the diastereomeric ratio varied as a function of the excited state that is generated, to yield mixtures of dimers 4 and 5 (anti-head-to-tail), or exclusively 5 in the triplet-sensitized photoreaction, in the presence of benzophenone. Density functional theory was used to elucidate a plausible detailed mechanism for the phototransformation, which aided in justifying the results that led to the corresponding dimers. X-ray crystallography allowed us to establish the stereochemical assignment of the obtained cyclobutyl rings. Thus, the use of solid-state or solution photochemistry can be used to gain control of diastereo- and regioselectivities in the formation of this important moiety.
Synthesis of Thia-Analogues of Calothrixin B Involving FeCl3-Mediated Domino Reaction
Ramalingam, Bose Muthu,Moorthy, Nachiappan Dhatchana,Vellaichamy, Elangovan,Mohanakrishnan, Arasambattu K.
supporting information, p. 133 - 137 (2016/12/26)
The total synthesis of thiacalothrixins, an isostere of the biologically important carbazoloquinone alkaloid calothrixin B, was achieved from ethyl benzo[b]thiophene-2-carboxylate. Alternatively, the multi-step synthesis of thiaisocalothrixins could be achieved from 3-methylbenzo[b]thiophene. A preliminary in vitro cytotoxicity evaluation of the synthesized thia analogues of calothrixins displayed promising potential against cancer cell cultures.
Palladium-catalyzed hydroxymethylation of aryl-and heteroarylboronic acids using aqueous formaldehyde
Yamamoto, Tetsuya,Zhumagazin, Azamat,Furusawa, Takuma,Tanaka, Ryoji,Yamakawa, Tetsu,Oe, Yohei,Ohtab, Tetsuo
supporting information, p. 3525 - 3529 (2015/01/09)
Cyclometallated NHC palladium complexes prepared from palladium(II) acetate [Pd(OAc)2] and unsymmetrical 1,3-diarylimidazolinium salts catalyzed the hydroxymethylation of (hetero)arylboronic acids using an excess amount of formalin to afford (hetero)arylm
