The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Zhangjie Shi - One of the best experts on this subject based on the ideXlab platform.
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direct cross coupling of benzyl alcohols to construct Diarylmethanes via palladium catalysis
Chemical Communications, 2015Co-Authors: Zhichao Cao, Ruyi Zhu, Jiangbo Wei, Zhangjie ShiAbstract:A direct arylation to furnish Diarylmethanes from benzyl alcohols was realized through Pd(PPh3)4-catalyzed Suzuki–Miyaura coupling via benzylic C–O activation in the absence of any additives. The arylation is compatible with various functional groups. This development provides an atom- and step-economic way to approach a Diarylmethane scaffold under mild and environmentally benign conditions.
Patrick J Walsh - One of the best experts on this subject based on the ideXlab platform.
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Ni(NIXANTPHOS)-Catalyzed Mono-Arylation of Toluenes with Aryl Chlorides and Bromides
2019Co-Authors: Hui Jiang, Shengchun Sha, Soo A Jeong, Brian C. Manor, Patrick J WalshAbstract:A nickel-catalyzed cross-coupling of toluene derivatives with both aryl bromides and chlorides using a NIXANTPHOS-ligated nickel(II) complex has been developed. The key factor to success is proposed to be the catalyst activation of toluene by a cation−π complex, enabling methyl arenes (pKa ≈ 43) to be deprotonated with the relatively mild base NaN(SiMe3)2. This method facilitates access to a variety of sterically and electronically diverse hetero- and nonheteroaryl-containing Diarylmethanes
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nickel catalyzed c sp3 h arylation of Diarylmethane derivatives with aryl fluorides
Journal of Organic Chemistry, 2018Co-Authors: Bihui Zhou, Patrick J WalshAbstract:A novel nickel-catalyzed C(sp3)-H arylation with nonactivated aryl fluorides is reported. The use of 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes) as a ligand was found to be critical to the success of the reaction. This new method enables the synthesis of a wide range of triarylmethane derivatives.
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nickel catalyzed allylic alkylation with Diarylmethane pronucleophiles reaction development and mechanistic insights
Angewandte Chemie, 2016Co-Authors: Shengchun Sha, Hui Jiang, Jianyou Mao, Ana Bellomo, Soo A Jeong, Patrick J WalshAbstract:Palladium-catalyzed allylic substitution reactions are among the most efficient methods to construct C-C bonds between sp(3)-hybridized carbon atoms. In contrast, much less work has been done with nickel catalysts, perhaps because of the different mechanisms of the allylic substitution reactions. Palladium catalysts generally undergo substitution by a "soft"-nucleophile pathway, wherein the nucleophile attacks the allyl group externally. Nickel catalysts are usually paired with "hard" nucleophiles, which attack the metal before C-C bond formation. Introduced herein is a rare nickel-based catalyst which promotes substitution with Diarylmethane pronucleophiles by the soft-nucleophile pathway. Preliminary studies on the asymmetric allylic alkylation are promising.
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nickel catalyzed arylation of heteroaryl containing Diarylmethanes exceptional reactivity of the ni nixantphos based catalyst
Chemical Science, 2016Co-Authors: Shengchun Sha, Xinyu Cao, Byeongseon Kim, Catherine Morgan, Rudan Huang, Xiaodong Yang, Patrick J WalshAbstract:Nickel(0)-catalyzed cross-coupling of heteroaryl-containing Diarylmethanes with both aryl bromides and chlorides has been achieved. The success of this reaction relies on the introduction of a unique nickel/NIXANTPHOS-based catalyst system, which provides a direct route to triarylmethanes from heteroaryl-containing Diarylmethanes. Reactivity studies indicate the Ni(NIXANTPHOS)-based catalyst exhibits enhanced reactivity over XANTPHOS derivatives and other Ni(phosphine)-based catalysts in the reactions examined.
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raising the pka limit of soft nucleophiles in palladium catalyzed allylic substitutions application of Diarylmethane pronucleophiles
ChemInform, 2014Co-Authors: Shengchun Sha, Jiadi Zhang, Patrick J Carroll, Patrick J WalshAbstract:A general method for the Pd-catalyzed allylic substitution with Diarylmethane derivatives is reported.
Lei Mei - One of the best experts on this subject based on the ideXlab platform.
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uranyl catalyzed hydrosilylation of para quinone methides access to Diarylmethane derivatives
Organic and Biomolecular Chemistry, 2021Co-Authors: Siyu Chen, Kang Liu, Liyong Yuan, Zhifang Chai, Lei Mei, Weiqun ShiAbstract:An efficient and convenient uranyl-catalyzed reductive hydrosilylation reaction of para-quinone methides (p-QMs) was developed by employing silane as the reductant. The hydrosilylation procedure using the UO2(NO3)2·6H2O/Et3SiH catalytic system proceeded smoothly and provided an expedient method for the construction of various Diarylmethane derivatives in one step with good to excellent yields.
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facile construction of diverse Diarylmethane scaffolds via uranyl catalyzed 1 6 addition reaction
Tetrahedron Letters, 2020Co-Authors: Siyu Chen, Kang Liu, Liyong Yuan, Yubao Zhao, Zhifang Chai, Lei MeiAbstract:Abstract A direct 1,6-addition route of p-QMs to synthesize substituted Diarylmethanes catalyzed by uranyl ion was developed. In our approach, the salient feature of this transformation is that abundant, underexploited, neglected and sequestrable depleted uranium made the reaction more sustainable. Moreover, Diarylmethane derivatives were delivered in moderate to high yields with broad scope and functional group tolerance. Facile operation and mild conditions offer a practical and attractive protocol.
Siyu Chen - One of the best experts on this subject based on the ideXlab platform.
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uranyl catalyzed hydrosilylation of para quinone methides access to Diarylmethane derivatives
Organic and Biomolecular Chemistry, 2021Co-Authors: Siyu Chen, Kang Liu, Liyong Yuan, Zhifang Chai, Lei Mei, Weiqun ShiAbstract:An efficient and convenient uranyl-catalyzed reductive hydrosilylation reaction of para-quinone methides (p-QMs) was developed by employing silane as the reductant. The hydrosilylation procedure using the UO2(NO3)2·6H2O/Et3SiH catalytic system proceeded smoothly and provided an expedient method for the construction of various Diarylmethane derivatives in one step with good to excellent yields.
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facile construction of diverse Diarylmethane scaffolds via uranyl catalyzed 1 6 addition reaction
Tetrahedron Letters, 2020Co-Authors: Siyu Chen, Kang Liu, Liyong Yuan, Yubao Zhao, Zhifang Chai, Lei MeiAbstract:Abstract A direct 1,6-addition route of p-QMs to synthesize substituted Diarylmethanes catalyzed by uranyl ion was developed. In our approach, the salient feature of this transformation is that abundant, underexploited, neglected and sequestrable depleted uranium made the reaction more sustainable. Moreover, Diarylmethane derivatives were delivered in moderate to high yields with broad scope and functional group tolerance. Facile operation and mild conditions offer a practical and attractive protocol.
Amitabha Sarkar - One of the best experts on this subject based on the ideXlab platform.
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palladium nanoparticle catalysis borylation of aryl and benzyl halides and one pot biaryl synthesis via sequential borylation suzuki miyaura coupling
Green Chemistry, 2012Co-Authors: Ansuman Bej, Dipankar Srimani, Amitabha SarkarAbstract:Palladium nanoparticles generated in PEG catalyze the reaction of bis(pinacolato)diboron with various aryl/benzyl halides to afford aryl/benzyl boronates in high yield. Arylboronates thus prepared, have been directly used in the Suzuki–Miyaura coupling reaction with different aryl halides and benzyl halides in a convenient one-pot, two-step solvent free green synthesis of unsymmetrical biaryls and Diarylmethanes.
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palladium nanoparticle catalyzed hiyama coupling reaction of benzyl halides
ChemInform, 2010Co-Authors: Dipankar Srimani, Ansuman Bej, Amitabha SarkarAbstract:Treatment of benzylic halides and tosylates with aryltrialkoxysilanes in the presence of Pd nanoparticles, generated in situ, provides a new and efficient approach to Diarylmethanes.
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palladium nanoparticle catalyzed hiyama coupling reaction of benzyl halides
Journal of Organic Chemistry, 2010Co-Authors: Dipankar Srimani, Ansuman Bej, Amitabha SarkarAbstract:An efficient Hiyama coupling reaction between benzylic halide and aryltrialkoxysilane using Pd nanoparticles has been developed. This procedure accommodates various functional groups to yield a diverse range of Diarylmethanes which are ubiquitous units of natural products and pharmaceuticals.