726-18-1Relevant academic research and scientific papers
Deoxygenation of tertiary and secondary alcohols with sodium borohydride, trimethylsilyl chloride, and potassium iodide in acetonitrile
Kato, Yuichi,Inoue, Tomoka,Furuyama, Yuuki,Ohgane, Kenji,Sadaie, Mahito,Kuramochi, Kouji
supporting information, (2021/11/16)
The deoxygenation of tertiary and secondary alcohols to give the corresponding alkanes is conventionally performed using an organosilane and a strong acid. In this study, a deoxygenation method was developed for tertiary and secondary alcohols, using trimethylsilane and trimethylsilyl iodide generated in situ from sodium borohydride and trimethylsilyl chloride, and trimethylsilyl chloride and potassium iodide, respectively. With our method, tertiary and secondary alcohols, which provided stable carbocations, were converted into the corresponding alkanes. This paper also presents the optimization of the reaction conditions, the reaction mechanism, as well as the scope and limitations of the method.
Boron carbonitride photocatalysts for direct decarboxylation: The construction of C(sp3)-N or C(sp3)-C(sp2) bonds with visible light
Shi, Jiale,Wang, Rong,Wang, Xinchen,Yuan, Tao,Zheng, Meifang
supporting information, p. 3945 - 3949 (2021/06/17)
A metal-free protocol is established for the decarboxylative N-H or C(sp2)-H functionalization of acidsviametal-free boron carbon nitride (BCN) photocatalysis, delivering the desired products under ambient conditions. This methodology is applicable to the late-stage modification of pharmaceutical molecules and gram-scale experiments as well as in the recovery and reuse of the photocatalysts without the loss of reactivity. The developed photochemical reaction system fulfills the requirements of green and sustainable chemistry.
Dynamic Kinetic Cross-Electrophile Arylation of Benzyl Alcohols by Nickel Catalysis
Guo, Peng,Wang, Ke,Jin, Wen-Jie,Xie, Hao,Qi, Liangliang,Liu, Xue-Yuan,Shu, Xing-Zhong
, p. 513 - 523 (2021/01/12)
Catalytic transformation of alcohols via metal-catalyzed cross-coupling reactions is very important, but it typically relies on a multistep procedure. We here report a dynamic kinetic cross-coupling approach for the direct functionalization of alcohols. The feasibility of this strategy is demonstrated by a nickel-catalyzed cross-electrophile arylation reaction of benzyl alcohols with (hetero)aryl electrophiles. The reaction proceeds with a broad substrate scope of both coupling partners. The electron-rich, electron-poor, and ortho-/meta-/para-substituted (hetero)aryl electrophiles (e.g., Ar-OTf, Ar-I, Ar-Br, and inert Ar-Cl) all coupled well. Most of the functionalities, including aldehyde, ketone, amide, ester, nitrile, sulfone, furan, thiophene, benzothiophene, pyridine, quinolone, Ar-SiMe3, Ar-Bpin, and Ar-SnBu3, were tolerated. The dynamic nature of this method enables the direct arylation of benzylic alcohol in the presence of various nucleophilic groups, including nonactivated primary/secondary/tertiary alcohols, phenols, and free indoles. It thus offers a robust alternative to existing methods for the precise construction of diarylmethanes. The synthetic utility of the method was demonstrated by a concise synthesis of biologically active molecules and by its application to peptide modification and conjugation. Preliminary mechanistic studies revealed that the reaction of in situ formed benzyl oxalates with nickel, possibly via a radical process, is an initial step in the reaction with aryl electrophiles.
Methylene Bridging Effect on the Structures, Lewis Acidities and Optical Properties of Semi-planar Triarylboranes
Doan, Thu-Hong,Chardon, Aurélien,Osi, Arnaud,Mahaut, Damien,Tumanov, Nikolay,Wouters, Johan,Champagne, Beno?t,Berionni, Guillaume
, p. 1736 - 1743 (2020/12/11)
Three synthetic methods towards semi-planar triarylboranes with two aryl rings connected by a methylene bridge have been developed. The fine-tuning of their stereoelectronic properties and Lewis acidities was achieved by introducing fluorine, methyl, methoxy, n-butyl and phenyl groups either at their exocyclic or bridged aryl rings. X-ray diffraction analysis and quantum-chemical calculations provided quantitative information on the structural distortion experienced by the near planar hydro-boraanthracene skeleton during the association with Lewis bases such as NH3 and F?. Though the methylene bridge between the ortho-positions of two aryl rings of triarylboranes decreased the Gibbs free energies of complexation with small Lewis bases by less than 5 kJ mol?1 relative to the classical Lewis acid BAr3, the steric shielding of the CH2 bridge is sufficient to avoid the formation of Lewis adducts with larger Lewis bases such as triarylphosphines. A newly synthesized spirocyclic amino-borane with a long intramolecular B?N bond that could be dissociated under thermal process, UV-irradiation, or acidic conditions might be a potential candidate in Lewis pairs catalysis.
Preparation of a platinum nanoparticle catalyst located near photocatalyst titanium oxide and its catalytic activity to convert benzyl alcohols to the corresponding ethers
Akiyama, Toshiki,Arisawa, Mitsuiro,Harada, Kazuo,Honma, Tetsuo,Naka, Hiroshi,Saito, Susumu,Wada, Yuki
, p. 22230 - 22237 (2021/07/02)
A novel platinum nanoparticle catalyst closely located near the surface of titanium oxide, PtNP/TiO2, has been prepared. This catalyst has both the properties of a photocatalyst and a metal nanoparticle catalyst, and acquired environmentally friendly catalytic activity, which cannot be achieved by just one of these catalysts, to afford ethers from benzyl alcohols under the wavelength of 420 nm.
Site-Selective Alkoxylation of Benzylic C?H Bonds by Photoredox Catalysis
Lee, Byung Joo,DeGlopper, Kimberly S.,Yoon, Tehshik P.
supporting information, p. 197 - 202 (2019/11/26)
Methods that enable the direct C?H alkoxylation of complex organic molecules are significantly underdeveloped, particularly in comparison to analogous strategies for C?N and C?C bond formation. In particular, almost all methods for the incorporation of alcohols by C?H oxidation require the use of the alcohol component as a solvent or co-solvent. This condition limits the practical scope of these reactions to simple, inexpensive alcohols. Reported here is a photocatalytic protocol for the functionalization of benzylic C?H bonds with a wide range of oxygen nucleophiles. This strategy merges the photoredox activation of arenes with copper(II)-mediated oxidation of the resulting benzylic radicals, which enables the introduction of benzylic C?O bonds with high site selectivity, chemoselectivity, and functional-group tolerance using only two equivalents of the alcohol coupling partner. This method enables the late-stage introduction of complex alkoxy groups into bioactive molecules, providing a practical new tool with potential applications in synthesis and medicinal chemistry.
Unusual transformation of 4-hydroxy/methoxybenzylic alcohols via C[sbnd]C ipso-substitution reaction using proton-exchanged montmorillonite as media
Chen, Dongyin,Chen, Xuan,Dong, Zezhong,Jiang, Nan,Li, Fei,Yun, Yangfang,Zhou, Yu
supporting information, (2020/11/12)
We present here proton-exchanged montmorillonite-mediated an unusual transformation of 4-hydroxy and 4-methoxybenzylic alcohols to form symmetrical benzylic ethers and diarylmethanes under mild conditions. Nuclear magnetic resonance spectroscopy and density functional theory calculations support a plausible mechanism, which includes a distinctive aromatic C[sbnd]C ipso-substitution reaction with a hydroxymethyl group as the C-based leaving group.
Dual Nickel- And Photoredox-Catalyzed Reductive Cross-Coupling of Aryl Halides with Dichloromethane via a Radical Process
Xu, Tao,Xu, Wenhao,Zheng, Purui
supporting information, (2020/11/13)
The first catalytic strategy to harness a new chloromethane radical from dichloromethane under dual Ni/photoredox catalytic conditions has been developed. Compared with traditional two-electron reductive process associated with metallic reductants, this method via a single-electron approach can proceed under exceptionally mild conditions (visible light, ambient temperature, no strong base) and exhibits complementary reactivity patterns. It affords a broad scope of many functional groups, including alkenyl, which suffers cyclopropanation in previous routes. The diarylmethane-d2 compounds can be readily available with this transformation.
Sc(OTf)3-Catalyzed Synthesis of Symmetrical Dithioacetals and Bisarylmethanes Using Nitromethane as a Methylene Source
Dethe, Dattatraya H.,Shukla, Manmohan,Dherange, Balu D.
supporting information, p. 5778 - 5782 (2020/07/30)
Use of nitromethane as an electrophilic methylene source for the synthesis of symmetrical dithioacetals and bisarylmethanes has been showcased using Sc(OTf)3 as a catalyst. The procedure allows straightforward access to the densely functionalized dithioacetals and bisarylmethanes under mild conditions. Additionally, the method has been applied for the synthesis of antimalarial tetramethyl mellotojaponin C and anticancer dimeric phloroglucinol derivative.
Nickel catalyzed deoxygenative cross-coupling of benzyl alcohols with aryl-bromides
Kumar Chenniappan, Vinoth,Peck, Devin,Rahaim, Ronald
supporting information, (2020/03/03)
A nickel-catalyzed cross-electrophile coupling of benzyl alcohols with aromatic bromides has been developed. This deoxygenative cross-coupling occurs under mild reaction conditions at ambient temperature affording diarylmethanes, or 1,3-diarylpropenes from benzyl allyl alcohols. The system demonstrated good chemoselectivity tolerating an assortment of reactive functional groups.
