14550-57-3Relevant articles and documents
Photocatalytic C-O Bond Cleavage of Alcohols Using Xanthate Salts
Nanjo, Takeshi,Matsugasako, Tatsuki,Maruo, Yuri,Takemoto, Yoshiji
supporting information, p. 359 - 363 (2022/01/15)
The homolytic cleavage of C-O bonds to afford alkyl radicals is an attractive yet challenging transformation in organic synthesis. Herein we describe a photocatalyzed deoxygenative C-C coupling reaction of xanthate salts, which can be easily prepared from the corresponding alcohols. The key to the success of this strategy is the low oxidation potential of the xanthate salt and the use of an appropriate phosphine to accelerate the desulfurative release of carbonyl sulfide.
A general copper-based photoredox catalyst for organic synthesis: Scope, application in natural product synthesis and mechanistic insights
Deldaele, Christopher,Michelet, Bastien,Baguia, Hajar,Kajouj, Sofia,Romero, Eugenie,Moucheron, Cecile,Evano, Gwilherm
, p. 621 - 629 (2018/10/04)
Organic transformations can broadly be classified into four categories including cationic, anionic, pericyclic and radical reactions. While the last category has been known for decades to provide remarkably efficient synthetic pathways, it has long been hampered by the need for toxic reagents, which considerably limited its impact on chemical synthesis. This situation has come to an end with the introduction of new concepts for the generation of radical species, photoredox catalysis – which simply relies on the use of a catalyst that can be activated upon visible light irradiation – certainly being the most efficient one. The state-of-the-art catalysts mostly rely on the use of ruthenium and iridium complexes and organic dyes, which still considerably limits their broad implementation in chemical processes: alternative readily available catalysts based on inexpensive, environmentally benign base metals are therefore strongly needed. Furthermore, expanding the toolbox of methods based on photoredox catalysis will facilitate the discovery of new light-mediated transformations. This article details the use of a simple copper complex which, upon activation with blue light, can initiate a broad range of radical reactions.
A General Copper Catalyst for Photoredox Transformations of Organic Halides
Michelet, Bastien,Deldaele, Christopher,Kajouj, Sofia,Moucheron, Cécile,Evano, Gwilherm
supporting information, p. 3576 - 3579 (2017/07/17)
A broadly applicable copper catalyst for photoredox transformations of organic halides is reported. Upon visible light irradiation in the presence of catalytic amounts of [(DPEphos)(bcp)Cu]PF6 and an amine, a range of unactivated aryl and alkyl halides were shown to be smoothly activated through a rare Cu(I)/Cu(I)?/Cu(0) catalytic cycle. This complex efficiently catalyzes a series of radical processes, including reductions, cyclizations, and direct arylation of arenes.
Aqueous reduction of iodosteroids to deoxysteroids
Liu, Changsheng,Sun, Lili,Li, Chunbao
, p. 309 - 312 (2014/06/09)
A new method for the reduction of iodosteroids to deoxysteroids has been developed using Zn, HCOOH and a catalytic amount of Aliquat 336 in water. In total, 13 iodosteroids were reduced in good to excellent yields. The higher solubilities of the substrates lead to the faster reactions, and the aqueous reaction was efficiently accelerated by granular polytetrafluoroethylene. The advantage of the aqueous system over eight organic solvents has also been demonstrated.
An efficient oxidative coupling method for synthesis of novel diastereomeric biaryl diols derived from estrone
Feng, Jie,Yang, Xin-Bin,Liang, Shuai,Zhang, Ji,Yu, Xiao-Qi
, p. 355 - 357 (2013/03/13)
An efficient oxidative coupling of estrogen derivatives was developed. Several 2-substitutent-17-deoxyestrones were applied to the aerobic oxidative coupling reactions catalyzed by CuCl2/TMEDA. The products were obtained as diastereoisomers wit
Photochemical Behavior of Δ4-3-Oxo, Δ5-7-Oxo, and Δ1-3-Oxo Steroids in Concentrated Acid Solution
Lupon, Pilar,Canals, Francesc,Iglesias, Arsenio,Ferrer, Joan C.,Palomer, Albert,et al.
, p. 2193 - 2198 (2007/10/02)
Irradiation with UV light of 5α-androst-1-en-3-one (9) in concentrated sulfuric acid leads to 15 and 16; similarly 4a-methyl-4a,5,6,7,8,8a-hexahydronaphthalen-2(1H)-one (10) gives 17 and 18.The formation of the four products is rationalized in terms of a photochemically induced 1,2-alkyl shift to the positively charged positions of the starting carbenium ions.On the other hand, irradiation under the same conditions of 4, 8, 7, and 11 yields, quantitatively, unchanged starting material, while the analogous bicyclic compound Δ1,9-10-methyl-2-octalone (1) has been reported to yield photorearrangement products.The lack of reactivity of 7 and 11 can be explained according to the proposed mechanism for the photorearrangement of 1.In the case of 4 and 8, the presence of the steroid rings C and D prevents the photorearrangement, but the mechanistic explanation of this effect cannot be determined from the present experimental data.
