40473-50-5Relevant articles and documents
Organic Br?nsted acid-catalyzed cycloadditions of o-quinone methides with 1, 3-dicarbonlys: Facile access to xanthenones and chromanones
Kokkuvayil Vasu, Radhakrishnan,Parameswaran, Sasikumar,Puthiyaparambath, Sharathna,Suresh Varma, Sanjay,Thoppe Sivakumar, Priyadarshini
, (2021/06/27)
The in-situ generation of o-quinone methides and their inverse-electron-demand Diels–Alder reaction in the presence of pentacarboxycyclopentadiene—an organic Br?nsted acid—has been reported. The synthesis of xanthenones and chromanones in good to excellen
Asymmetric Transfer Hydrogenation of o-Hydroxyphenyl Ketones: Utilizing Directing Effects That Optimize the Asymmetric Synthesis of Challenging Alcohols
Clarkson, Guy J.,Wills, Martin,Zheng, Ye
supporting information, (2020/05/05)
A systematic range of o-hydroxyphenyl ketones were reduced under asymmetric transfer hydrogenation conditions using the C3-tethered catalyst 2. Two directing effects, i.e., an o-hydroxyphenyl coupled to a bulky aromatic on the opposite side of the ketone substrate, combine in a matched manner to deliver reduction products with very high enantiomeric excess.
Regio- A nd Enantioselective Friedel-Crafts Benzhydrylation of Indoles in Carbocyclic Ring with ortho-Quinomethanes: Access to Chiral Diarylindolylmethanes
Chu, Ming-Ming,Chen, Xue-Yang,Wang, Yi-Feng,Qi, Suo-Suo,Jiang, Zhen-Hui,Xu, Dan-Qian,Xu, Zhen-Yuan
, p. 9491 - 9502 (2020/09/03)
The functionalization of indoles in the carbocyclic ring has been achieved via organocatalytic enantioselective Friedel-Crafts benzhydrylation of hydroxyindoles with in situ generated ortho-quinomethanes in oil-water biphases, allowing an efficient access to varied diarylindolylmethanes with a wide substrate scope. The high yields, excellent stereoselectivities, mild conditions, low catalyst loading, and easy scalability also demonstrated the interest of this novel methodology.
Ruthenium-Catalyzed Direct Asymmetric Reductive Amination of Diaryl and Sterically Hindered Ketones with Ammonium Salts and H2
Hu, Le' an,Zhang, Yao,Zhang, Qing-Wen,Yin, Qin,Zhang, Xumu
supporting information, p. 5321 - 5325 (2020/02/28)
A Ru-catalyzed direct asymmetric reductive amination of ortho-OH-substituted diaryl and sterically hindered ketones with ammonium salts is reported. This method represents a straightforward route toward the synthesis of synthetically useful chiral primary diarylmethylamines and sterically hindered benzylamines (up to 97 % yield, 93–>99 % ee). Elaborations of the chiral amine products into bioactive compounds and a chiral ligand were demonstrated through manipulation of the removable and convertible -OH group.
Synthesis of 2 H-Chromenes via Unexpected [4 + 2] Annulation of Alkynyl Thioethers with o-Hydroxybenzyl Alcohols
Bu, Hao-Zhen,Li, Hang-Hao,Luo, Wen-Feng,Luo, Chen,Qian, Peng-Cheng,Ye, Long-Wu
supporting information, p. 648 - 652 (2020/01/31)
A novel Br?nsted acid-catalyzed reaction of alkynyl thioethers with o-hydroxybenzyl alcohols via an unexpected formal [4 + 2] annulation has been developed. This metal-free protocol leads to the facile and practical synthesis of valuable polysubstituted 2
Efficient visible-light photocatalytic aerobic oxidation of cyclic sulfamides to imines
Ming, Zong-Yao,Li, Kang-Rui,Meng, Fan-Jie,Shi, Lei,Jiang, Wen-Feng
supporting information, (2020/06/17)
A highly efficient photocatalytic aerobic oxidation of cyclic sulfamides to synthesize cyclic N-sulfonyl imines with Ir(ppy)2(dtbpy)PF6 as photocatalyst is reported. These environmentally friendly transformations exihibit good to excellent isolated yields and good generality with respect to both five-membered and six-membered cyclic sulfamides.
Catalytic Asymmetric Three-component Hydroacyloxylation/ 1,4-Conjugate Addition of Ynamides
Cao, Weidi,Feng, Xiaoming,Jiang, Mingyi,Li, Xiangqiang,Zhan, Tangyu
supporting information, (2020/06/17)
A highly enantioselective three-component hydroacyloxylation/1,4-conjugate addition of ortho-hydroxybenzyl alcohols, ynamides and carboxylic acids was developed under mild reaction conditions in the presence of a chiral N,N′-dioxide/Sc(OTf)3 complex, which went through in situ generated ortho-quinone methides with α-acyloxyenamides, delivering a range of corresponding chiral α-acyloxyenamides derivatives containing gem(1,1)-diaryl skeletons in moderate to good yields with excellent ee values. The scale-up experiment and further derivation showed the practicality of this catalytic system. In addition, a possible catalytic cycle and transition state model was proposed to elucidate the origin of the stereoselectivity based on X-ray crystal structure of the α-acyloxyenamide intermediate and product.
[4 + 2]-Cycloaddition and 1,4-Addition of ortho-Quinone Methides by a Chiral Crotyl Silane
Wong, Christopher R.,Hummel, Gerald,Cai, Yongqi,Schaus, Scott E.,Panek, James S.
supporting information, p. 32 - 35 (2019/01/04)
Anhydrous FeCl3 in the presence of 2,6-lutidine promotes the substrate-controlled enantioselective [4 + 2]-cycloaddition and crotylation reaction between an enantioenriched (S,E)-crotyl silane and in situ generated ortho-quinone methides (oQMs)
A base-promoted cascade reaction of α,β-unsaturated: N -tosylhydrazones with o -hydroxybenzyl alcohols: Highly regioselective synthesis of N-sec -alkylpyrazoles
Chen, Lian-Mei,Zhao, Juan,Xia, An-Jie,Guo, Xiao-Qiang,Gan, Ya,Zhou, Chuang,Yang, Zai-Jun,Yang, Jun,Kang, Tai-Ran
supporting information, p. 8561 - 8570 (2019/10/02)
An efficient method for the synthesis of N-sec-alkylpyrazoles through a base-promoted cascade cyclization/Michael addition reaction of α,β-unsaturated N-tosylhydrazones with ortho-hydroxybenzyl alcohols has been developed. The desired products containing di- or triaryl groups at the same carbon atom were afforded in good to excellent yields with excellent regioselectivities (>20:1). Moreover, a three-component reaction of ortho-hydroxybenzyl alcohols, α,β-unsaturated N-tosylhydrazones and saturated N-tosylhydrazones also took place to afford pyrazoles in good yields. This reaction offers a new route to triarylmethanes with a simple operation and is applicable for large-scale synthesis.
A Simple Synthesis of Densely Substituted Benzofurans by Domino Reaction of 2-Hydroxybenzyl Alcohols with 2-Substituted Furans
Abaev, Vladimir T.,Chalikidi, Petrakis N.,Kekhvaeva, Anna E.,Makarov, Anton S.,Trushkov, Igor V.,Uchuskin, Maxim G.
, p. 3747 - 3757 (2019/09/30)
The Br?nsted acid-catalyzed cascade synthesis of densely substituted benzofurans from easily available salicyl alcohols and biomass-derived furans has been developed. The disclosed sequence includes the intermediate formation of 2-(2-hydroxybenzyl)furans