Selective sulfonylation and isonitrilation of para-quinone methides employing TosMIC as a source of sulfonyl group or isonitrile group

• Chuanhua Qu,
• Run Huang,
• Yong Li,
• Tong Liu,
• Yuan Chen and
• Guiting Song

Beilstein J. Org. Chem. 2021, 17, 2822–2831, doi:10.3762/bjoc.17.193

• sulfones is a valuable and appealing task in synthetic chemistry. Traditionally, diarylmethyl sulfones are synthesized by transition-metal-catalyzed deoxy C–S bond-coupling reaction of sodium arylsulfinates with diarylmethanols [11], C–H functionalization of alkyl sulfones with aryl halides [12], and via a

Recent advances in the syntheses of anthracene derivatives

• Giovanni S. Baviera and
• Paulo M. Donate

Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131

• via an acid-catalyzed cyclization of O-protected ortho-acetal diarylmethanols 81a and 81b as a new type of reactants (Scheme 19) [52]. To carry out the cyclization step, this new methodology employed a diluted aqueous methanolic solution of HCl at room temperature. This step was based on a modified

• sequential transformations of the resulting adduct into the protected diarylmethanols 81a and 81b. The scope of the reaction consisted of five examples (82a–e) that were obtained in moderate yields (30–68%). According to the authors, the reaction conditions were the mildest ever used in this type of

• ortho-acetal diarylmethanols. Lewis acid-mediated regioselective cyclization of asymmetric diarylmethine dipivalates and diarylmethine diols. BF3·OEt2/CF3SO3H-mediated cyclodehydration reactions of 2-(arylmethyl)benzaldehydes and 2-(arylmethyl)benzoic acids. Synthesis of 2,3,6,7

A selective removal of the secondary hydroxy group from ortho-dithioacetal-substituted diarylmethanols

• Anna Czarnecka,
• Emilia Kowalska,
• Agnieszka Bodzioch,
• Joanna Skalik,
• Marek Koprowski,
• Krzysztof Owsianik and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2018, 14, 1229–1237, doi:10.3762/bjoc.14.105

• % yields and is recommended for the substrates containing sulfur atoms, for which transition metal-induced reactions fail. Keywords: diarylmethanes; diarylmethanols; 1,3-dithiane; selective reduction; sodium cyanoborohydride; zinc iodide; Introduction In last decades, diarylmethanes, such as I–IV and

• –CF3COOH, TMSCl/NaI failed to reduce secondary OH groups in diheteroaromatic systems and the reduction with H2/Pd/C-ZnBr2 was very slow [32]. On the other hand, some rigid diarylmethanols were successfully reduced to benzo[b]indeno[2,1-d]thiophenes using the Et3SiH–CF3COOH system which was reported in the

• patent literature [44]. Benzophenones were also reduced to diarylmethanes using supercritical iPrOH at 350 °C [1], BF3·OEt2/H2O [33] and PhSiH3/MoCl2O2(H2O)2 [45]. The reductive deoxygenation reactions of diarylmethanols proceed via carbocationic species, which are formed by protonation or complexation

Copper-mediated arylation with arylboronic acids: Facile and modular synthesis of triarylmethanes

• H. Surya Prakash Rao and
• A. Veera Bhadra Rao

Beilstein J. Org. Chem. 2016, 12, 496–504, doi:10.3762/bjoc.12.49

• which the final step is the copper(II)-catalyzed arylation of diarylmethanols with arylboronic acids. By using this protocol a variety of symmetrical and unsymmetrical triarylmethanes were synthesized. As an application of the newly developed methodology, we demonstrate a high-yielding synthesis of the

• variety of triarylmethanes through substitution of C(sp3)–OH in diarylmethanols with arylboronic acids (Scheme 1B). We reasoned that since diarylmethanols with two different aromatic rings can be made by a wide variety of methods [53][54] (e.g., addition of an aryl carbanion to an aryl aldehyde and a

• report a copper(II) triflate-catalyzed modular synthesis of triarylmethanes by employing diarylmethanols 9 and arylboronic acids 10. It is advantageous to employ a base metal catalyst such as copper(II) triflate instead of palladium [55][56] or nickel (Ni) [57] catalysts and to avoid the use of phosphine

Continuous flow enantioselective arylation of aldehydes with ArZnEt using triarylboroxins as the ultimate source of aryl groups

• Julien Rolland,
• Xacobe C. Cambeiro,
• Carles Rodríguez-Escrich and
• Miquel A. Pericàs

Beilstein J. Org. Chem. 2009, 5, No. 56, doi:10.3762/bjoc.5.56

• flow system for the synthesis of enantioenriched diarylmethanols from aldehydes is described. The system uses an amino alcohol-functionalized polystyrene resin as the catalyst, and the arylating agent is conveniently prepared by transmetallation of triarylboroxins with diethylzinc. Keywords

• : asymmetric synthesis; continuous flow; diarylmethanols; solid-supported catalyst; triarylboroxins; Introduction Diarylmethanols constitute the basic scaffold in several important drugs such as antihistamines and muscle relaxants (R)-neobenodine, (R)-orphenadrine or (S)-carbinoxamine (Figure 1) [1]. Despite

• -pass, continuous flow highly enantioselective ethylation of aldehydes characterized by very short residence times (down to 2.8 min) [23]. According to these precedents, we considered that 2 could be a good candidate for a planned continuous enantioselective production of diarylmethanols. When a large