cas 63194-80-9, (6E)-6-[(4-methoxyphenyl)methylidene]-1,3-benzodioxol-5(6H)-one

Articles about 63194-80-9Total 6 be found

Asymmetric Catalytic [4+5] Annulation of ortho-Quinone Methides with Vinylethylene Carbonates and its Extension to Stereoselective Tandem Rearrangement
Palladium-catalyzed asymmetric [4+5] annulation of ortho-quinone methides (o-QMs) with substituted vinylethylene carbonates (VECs) is described for the first time, giving a novel enantioselective approach to chiral nine-membered benzoheterocycles. Based on this designed [4+5] annulation, an unprecedented silica gel-promoted tandem rearrangement reaction featuring a unique asymmetric aromatic Claisen rearrangement is explored at room temperature, offering a new method for asymmetric construction of all-carbon quaternary stereocenters embedded in chiral functionalized homoallylic alcohols.
An, Xian-Tao,Du, Ji-Yuan,Jia, Zhi-Long,Zhang, Qing,Yu, Ke-Yin,Zhang, Yi-Zhou,Zhao, Xian-He,Fang, Ran,Fan, Chun-An
supporting information
p. 3803 - 3809
(2020/03/19)

Highly Regio-, Diastereo-, and Enantioselective Synthesis of Tetrahydroazepines and Benzo[b]oxepines through Palladium-Catalyzed [4+3] Cycloaddition Reactions
A novel Pd0-catalyzed asymmetric [4+3] annulation reaction of two readily accessible starting materials has been developed for building seven-membered heterocyclic architectures. The potential [3+2] side pathway could be suppressed though fine tuning of the conditions. A broad scope of cycloaddition donors and acceptors participated in the transformation with excellent chemo-, regio-, diastereo-, and enantioselectivtities, leading to valuable tetrahydroazepines and benzo[b]oxepines.
Trost, Barry M.,Zuo, Zhijun
supporting information
p. 1243 - 1247
(2019/11/25)

Organophotoredox-catalyzed intermolecular Oxa-[4+2] cycloaddition reactions
An intermolecular oxa-[4+2] cycloaddition reaction promoted by a thioxanthylium photoredox catalyst under irradiation with green light has been developed. The reaction of ortho-quinone methides with styrenes smoothly affords the desired cycloadducts. Espe
Tanaka, Kenta,Omata, Daichi,Asada, Yosuke,Hoshino, Yujiro,Honda, Kiyoshi
p. 10669 - 10678
(2019/08/22)

Transition-Metal-Free [4+3]-Cycloaddition of ortho-Quinone Methides and Isomünchnones: Catalytic and Diastereoselective Assembly of Oxa-bridged Oxazocine Scaffolds
Cycloadditions are powerful processes to synthesize complex polycyclic scaffolds. Herein, we disclose a [4+3]-cycloaddition between an in situ generated ortho-quinone methide and an isomünchnone to yield oxa-bridged oxazocine cores, generating N2 and H2O as the sole by-products. Using only catalytic amounts of camphorsulfonic acid, it is possible to generate both reactive intermediates in one step, eliminating the need for rhodium catalysts generally employed for isomünchnone formation. Spectroscopic data and X-ray crystallography indicate the formation of the syn diastereomer, with the main side-product arising from a hydrate participating in a competing [4+2]-cycloaddition pathway.
Lam, Heather,Qureshi, Zafar,Wegmann, Marcus,Lautens, Mark
supporting information
p. 16185 - 16189
(2018/11/23)

N-Heterocyclic Carbene-Catalyzed [4 + 2] Cyclization of Saturated Carboxylic Acid with o-Quinone Methides through in Situ Activation: Enantioselective Synthesis of Dihydrocoumarins
An N-heterocyclic carbene (NHC)-catalyzed formal [4 + 2] synthesis of dihydrocoumarins was realized from saturated carboxylic acids and o-quinone methides via an in situ activation strategy. This protocol results in excellent diastereoselectivity and enantioselectivity and good yields and uses readily available and inexpensive starting materials.
Wang, Yuanfeng,Pan, Jian,Dong, Jingjiao,Yu, Chenxia,Li, Tuanjie,Wang, Xiang-Shan,Shen, Shide,Yao, Changsheng
p. 1790 - 1795
(2017/02/10)

Formal Asymmetric Catalytic Thiolation with a Bifunctional Catalyst at a Water-Oil Interface: Synthesis of Benzyl Thiols
The enantioselective conjugated addition of tritylthiol to in situ generated ortho-quinone methides (o-QMs) is catalyzed by an acid-base bifunctional squaramide organocatalyst. The transformation proceeds with high yield (up to 99%) and stereoselectivity (up to 97:3 e.r.) using water as solvent under mild conditions. The catalyst system provides a new strategy for the synthesis of optically active benzyl mercaptans. Control experiments suggested that o-QMs are generated by the tertiary amine moiety of the squaramide organocatalyst and that the water-oil biphase is crucial for achieving high reactivity and stereoselectivity.
Guo, Wengang,Wu, Bo,Zhou, Xin,Chen, Ping,Wang, Xu,Zhou, Yong-Gui,Liu, Yan,Li, Can
supporting information
p. 4522 - 4526
(2015/04/14)