87666-32-8Relevant academic research and scientific papers
Energy-Transfer-Mediated Photocatalysis by a Bioinspired Organic Perylenephotosensitizer HiBRCP
Zhang, Yan,Xia, Mingze,Li, Min,Ping, Qian,Yuan, Zhenbo,Liu, Xuanzhong,Yin, Huimin,Huang, Shuping,Rao, Yijian
, p. 15284 - 15297 (2021/11/01)
Energy transfer plays a special role in photocatalysis by utilizing the potential energy of the excited state through indirect excitation, in which a photosensitizer determines the thermodynamic feasibility of the reaction. Bioinspired by the energy-transfer ability of natural product cercosporin, here we developed a green and highly efficient organic photosensitizer HiBRCP (hexaisobutyryl reduced cercosporin) through structural modification of cercosporin. After structural manipulation, its triplet energy was greatly improved, and then, it could markedly promote the efficient geometrical isomerization of alkenes from the E-isomer to the Z-isomer. Moreover, it was also effective for energy-transfer-mediated organometallic catalysis, which allowed realization of the cross-coupling of aryl bromides and carboxylic acids through efficient energy transfer from HiBRCP to nickel complexes. Thus, the study on the relationship between structural manipulation and their photophysical properties provided guidance for further modification of cercosporin, which could be applied to more meaningful and challenging energy-transfer reactions.
Rh-Catalyzed Asymmetric Hydrogenation of β-Branched Enol Esters for the Synthesis of β-Chiral Primary Alcohols
Liu, Chong,Yuan, Jing,Zhang, Jian,Wang, Zhihui,Zhang, Zhenfeng,Zhang, Wanbin
supporting information, p. 108 - 111 (2018/01/17)
An asymmetric hydrogenation of β-branched enol esters has been developed for the first time, providing a new route for the synthesis of β-chiral primary alcohols. Using a (S)-SKP-Rh complex bearing a large bite angle and enol ester substrates possessing an O-fomyl directing group, the desired products were obtained in quantitative yields and with excellent enantioselectivities.
Copper(i)-catalysed asymmetric allylic reductions with hydrosilanes
Thanh Nguyen,Thiel, Niklas O.,Teichert, Johannes F.
supporting information, p. 11686 - 11689 (2017/11/03)
A copper(i)-catalysed asymmetric allylic reduction enables a regio- and stereoselective transfer of a hydride nucleophile in an SN2′-fashion onto allylic bromides. This transformation represents a conceptually orthogonal approach to allylic substitution reactions with carbon nucleophiles. A copper(i) complex based upon a chiral N-heterocyclic carbene (NHC) ligand allows for stereoselectivity reaching 99% ee. The catalyst enables a stereoconvergent reaction irrespective of the double bond configuration of the starting materials.
BICYCLIC 1,3,4-OXADIAZOLE DERIVATIVES AS SPHINGOSINE-1-PHOSPHATE RECEPTORS' MODULATORS
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Paragraph 0157; 0158; 0159, (2016/06/06)
The present invention relates to bicyclic 1,3,4-oxadiazole derivatives, processes for preparing them, pharmaceutical compositions containing them and their use as pharmaceuticals as modulators of sphingosine-1-phosphate receptors.
A Bio-Inspired, Catalytic e → Z Isomerization of Activated Olefins
Metternich, Jan B.,Gilmour, Ryan
supporting information, p. 11254 - 11257 (2015/09/21)
Herein, Natures flavin-mediated activation of complex (poly)enes has been translated to a small molecule paradigm culminating in a highly (Z)-selective, catalytic isomerization of activated olefins using (-)-riboflavin (up to 99:1 Z/E). In contrast to the prominent Z → E isomerization of the natural system, it was possible to invert the directionality of the isomerization (E → Z) by simultaneously truncating the retinal scaffold, and introducing a third olefin substituent to augment A1,3-strain upon isomerization. Consequently, conjugation is reduced in the product chromophore leading to a substrate/product combination with discrete photophysical signatures. The operationally simple isomerization protocol has been applied to a variety of enone-derived substrates and showcased in the preparation of the medically relevant 4-substituted coumarin scaffold. A correlation of sensitizer triplet energy (ET) and reaction efficiency, together with the study of additive effects and mechanistic probes, is consistent with a triplet energy transfer mechanism.
1,3,4-ALKENYL OXADIAZOLE AMINO ACID DERIVATIVES AS SPHINGOSINE-1-PHOSPHATE RECEPTORS' MODULATORS
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Page/Page column 21, (2015/06/03)
The present invention relates to 1,3,4-alkenyl oxadiazole amino acid derivatives of formulae I and II, processes for preparing them, pharmaceutical compositions containing them and their use as pharmaceuticals as modulators of sphingosine-1-phosphate receptors.
General, robust, and stereocomplementary preparation of β-ketoester enol tosylates as cross-coupling partners utilizing TsCl-N-methylimidazole agents
Nakatsuji, Hidefumi,Ueno, Kanako,Misaki, Tomonori,Tanabe, Yoo
supporting information; scheme or table, p. 2131 - 2134 (2009/05/26)
(Chemical Equation Presented) We have developed a general, robust, and cost-effective method for the (E)- or (Z)-stereocomplementary enol tosylation of β-ketoesters using TsCl-N-methylimidazole (NMI)-Et3N or LiOH. TsCl coupled with NMI formed a
Stereochemistry of the Reactions of CuI Catalyzed Grignard Reagents with Ethyl (E)- and (Z)-β-Chlorocinnamates
Jalander, Lars,Broms, Merete
, p. 173 - 178 (2007/10/02)
Ethyl (E)- and (Z)-3-chloro-3-phenyl-2-propenoate were prepared and separated.The (Z)-isomer gave β-alkylated ethyl cinnamates in good yield when reacted with alkyl Grignard reagents in the presence of 10percent CuI.The (Z)-isomer reacted with retention o
