3899-19-2Relevant academic research and scientific papers
Bisketene Equivalents as Diels-Alder Dienes
Dissanayake, Isuru,Hart, Jacob D.,Becroft, Emma C.,Sumby, Christopher J.,Newton, Christopher G.
supporting information, p. 13328 - 13333 (2020/09/03)
2,5-Bis(tert-butyldimethylsilyloxy)furans are established as vicinal bisketene equivalents for application as dienes in the Diels-Alder reaction. Cycloaddition with olefinic dienophiles, under exceptionally mild conditions, enables convergent access to highly substituted para-hydroquinones in unprotected form via a one-pot Diels-Alder/ring-opening/tautomerization sequence. The synthesis of para-benzoquinones from acetylenic dienophiles, including benzynes, is also demonstrated, and 2,5-bis(tert-butyldimethylsilyloxy)pyrroles are established as competent dienes for the synthesis of para-iminoquinones. Application in natural product synthesis enables gram-scale access to the neuroprotective agent (±)-indanostatin.
Catalytic asymmetric [2+2] cycloaddition between quinones and fulvenes and a subsequent stereoselective isomerization to 2,3-dihydrobenzofurans
Zheng, Haifeng,Xu, Chaoran,Wang, Yan,Kang, Tengfei,Liu, Xiaohua,Lin, Lili,Feng, Xiaoming
, p. 6585 - 6588 (2017/07/10)
The catalytic enantioselective [2+2] cycloaddition between quinones and fulvenes was achieved, for the first time, by the use of a chiral copper(ii) complex catalyst. The transformation afforded a series of enantiomerically enriched [6,4,5]-tricyclic cyclobutane derivatives in good yields with excellent regio- and stereoselectivities. Furthermore, the [2+2] adducts could be easily converted into formal [3+2] adducts efficiently and stereoselectively.
Enantioselective rare-earth catalyzed quinone Diels-Alder reactions
Evans, David A.,Wu, Jimmy
, p. 10162 - 10163 (2007/10/03)
A highly enantioselective, quinone Diels-Alder reaction catalyzed by chiral samarium and gadolinium pyridyl-bis(oxazoline) (pybox) complexes has been developed. The reaction scope has been extended to include three quinones and five dienes, all of which e
Utilization of derivatives of 2,5-dihydroxyphenyl-carboxylic acids, their homologs, and their salts in preparation of a cosmetic or dermatological composition with a depigmenting action
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, (2008/06/13)
A cosmetic or dermatological composition with a depigmenting action comprises derivatives of 2,5-dihydroxyphenylcarboxylic acids, their homologs, and their salts, with the derivatives having the following structural formula: STR1 wherein: R1 re
