65490-14-4Relevant academic research and scientific papers
Practical, Large-Scale Preparation of Benzoxepines and Coumarins through Rhodium(III)-Catalyzed C-H Activation/Annulation Reactions
Gulías, Moisés,Marcos-Atanes, Daniel,Mascare?as, José L.,Font, Marc
supporting information, p. 1669 - 1673 (2019/09/04)
Herein we disclose the assembly of benzoxepines and coumarins from 2-alkenylphenol precursors using [Cp*RhCl2]2 as the precatalyst and alkynes or carbon monoxide as reacting partners. The preparation of benzoxepines and coumarins can be scaled up to 33 mmol using low catalyst loadings.
OH-directed alkynylation of 2-vinylphenols with ethynyl benziodoxolones: A fast access to terminal 1,3-enynes
Finkbeiner, Peter,Kloeckner, Ulrich,Nachtsheim, Boris J.
supporting information, p. 4949 - 4952 (2015/04/14)
The first direct alkynylation of 2-vinylphenols was developed. The rationally optimized hypervalent iodine reagent TIPS-EBX in combination with [(CpRhCl2)2] as a C-H-activating transition metal catalyst enables the construction of a variety of highly substituted 1,3-enynes in high yields of up to 98 %. This novel C-H activation method shows excellent chemoselectivity and exclusive (Z)-stereoselectivity, and it is also remarkably mild and tolerates a variety of functional groups. Furthermore, synthetic modifications of the resulting 1,3-enynes were demonstrated. To our knowledge, this is the first example for an OH-directed C-H alkynylation with hypervalent iodine reagents.
Rhodium(III)-catalyzed dearomatizing (3 + 2) annulation of 2-alkenylphenols and alkynes
Seoane, Andrés,Casanova, Noelia,Qui?ones, Noelia,Mascare?as, José L.,Gulías, Moisés
supporting information, p. 7607 - 7610 (2014/06/10)
Appropriately substituted 2-alkenylphenols undergo a mild formal [3C+2C] cycloaddition with alkynes when treated with a Rh(III) catalyst and an oxidant. The reaction, which involves the cleavage of the terminal C-H bond of the alkenyl moiety and the dearomatization of the phenol ring, provides a versatile and efficient approach to highly appealing spirocyclic skeletons and occurs with high selectivity.
Ethylene glycol as hydrogen donor for the syntheses of thymol analogues via hydrolysis of 4-methylcoumarins
Chang, Junbiao,Wang, Shuyang,Shen, Zhenhua,Huang, Gang,Zhang, Yueteng,Zhao, Jing,Li, Changwei,Fan, Fangfang,Song, Chuanjun
supporting information, p. 6755 - 6757,3 (2012/12/12)
Treatment of 4-methylcoumarins with potassium hydroxide in ethylene glycol resulted in the formation of the 'normal' 2-isopropenylphenols and/or the 'abnormal' 2-isopropylphenols depending on the nature of the substrates. The solvent ethylene glycol was b
Radical induced fragmentation in a benzoxocane ring system: Application to the synthesis of elvirol and a formal synthesis of 7,8-dihydroxycalamenene
Roy, Amalesh,Tuhina, Kazi,Biswas, Bidyut,Venkateswaran, Ramanathapuram V.
scheme or table, p. 6575 - 6580 (2012/08/29)
A novel radical induced fragmentation in a benzoxocane ring system has been employed for a synthesis of elvirol 8 and an advanced intermediate in the synthesis of 7,8-dihydroxycalamenene 20. The coumarins 9, 22 were taken through a sequence of reactions t
Synthesis of coumarins via Pd-catalyzed oxidative cyclocarbonylation of 2-vinylphenols
Ferguson, Jamie,Zeng, Fanlong,Alper, Howard
supporting information, p. 5602 - 5605,4 (2012/12/12)
Palladium-catalyzed oxidative cyclocarbonylation of 2-vinylphenols constitutes a simple, direct method for the synthesis of coumarins. The reaction conditions, employing low pressures of CO, and air or 1,4- benzoquinone as the oxidant, are attractive in terms of environmental considerations and operational simplicity. Coumarins with a variety of functional groups were prepared in yields up to 85%.
