164025-71-2Relevant academic research and scientific papers
Synthesis of Novel C 2-Symmetric Sulfur-Based Catalysts: Asymmetric Formation of Halo- and Seleno-Functionalized Normal- and Medium-Sized Rings
Jana, Sadhan,Kumar, Sangit,Rathore, Vandana,Verma, Ajay
supporting information, p. 1667 - 1672 (2019/08/28)
The synthesis of novel, highly functionalized, C 2 -symmetric sulfur-based catalysts is developed and their catalytic applications are explored in asymmetric bromo-, iodo- and seleno-functionalizations of alkenoic acids. This protocol provides
Electrophilic Bromolactonization of Cyclopropyl Carboxylic Acids Using Lewis Basic Sulfide Catalyst
Ke, Zhihai,Wong, Ying-Chieh,See, Jie Yang,Yeung, Ying-Yeung
supporting information, p. 1719 - 1724 (2016/06/09)
A highly facile and efficient electrophilic bromolactonization of cyclopropylcarboxylic acids could be effected by a Lewis basic sulfide catalyst. Mechanistic studies performed revealed that the cyclopropane substrates could undergo radical bromination upon exposure to light, yielding a mixture of regioisomers. In stark contrast, the Lewis basic sulfide catalyst could promote the electrophilic bromolactonization and yield the Markovnikov product exclusively.
CuX2-mediated oxybromination/aminochlorination of unsaturated amides: Synthesis of iminolactones and lactams
Zhang, Zhi-Qiang,Liu, Feng
supporting information, p. 6690 - 6693 (2015/06/25)
We report herein a CuX2-mediated halocyclization of γ,δ-unsaturated amides for the synthesis of functionalized iminolactones and lactams respectively under mild reaction conditions. Mechanism studies indicated that N-attack cyclization was via a radical route while oxycyclization was via a nucleophilic attack on the activated CC bond.
Enantioselective bromoaminocyclization using amino-thiocarbamate catalysts
Zhou, Ling,Chen, Jie,Tan, Chong Kiat,Yeung, Ying-Yeung
supporting information; experimental part, p. 9164 - 9167 (2011/08/04)
A facile and efficient enantioselective bromoaminocyclization of unsaturated sulfonamides has been developed using an amino-thiocarbamate catalyst. A range of enantioenriched pyrrolidines were prepared with up to 99% yield and 99% ee. The corresponding lactams could be obtained through oxidation of the pyrrolidines.
Asymmetric bromolactonization using amino-thiocarbamate catalyst
Zhou, Ling,Tan, Chong Kiat,Jiang, Xiaojian,Chen, Feng,Yeung, Ying-Yeung
supporting information; experimental part, p. 15474 - 15476 (2011/02/21)
A novel amino-thiocarbamate-catalyzed bromolactonization of unsaturated carboxylic acids has been developed. The scope of the reaction is evidenced by 22 examples of γ-lactones with up to 99% yield and 93% ee. The protocol was applied in the enantioselective synthesis of the key intermediates of VLA-4 antagonists.
Erogorgiaene congeners and methods and intermediates useful in the preparation of same
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Page/Page column 28, (2010/04/30)
Disclosed are compounds having the formula: wherein R21 is an alkyl, aryl, alkoxy, hydroxy, or amino group or a halogen atom; wherein R2 is hydrogen or an alkyl, aryl, alkoxy, or amino group; wherein R23 and R24 are independently selected from hydrogen, an alkyl, aryl, alkoxy, hydroxy, or amino group, and a halogen atom or wherein R23 and R24, taken together with the carbon atom to which they are bound, form a ring; wherein R25 is hydrogen, an alkyl, aryl, alkoxy, hydroxy, or O-silyl group or a halogen atom; wherein Z, taken together with the carbons to which it is bonded, forms a 5-12 membered ring; and wherein Y is an electron withdrawing group. These compounds can be used to prepare erogorgiaene congeners, such as erogorgiaene, pseudopterosin A, helioporin E, pseudopteroxazole, colombiasin A, elisapoterosin B, elisabethadione, p-benzoquinone natural products, ileabethin, sinulobtain B, sinulobtain C, and sinulobtain D.
Direct synthesis of (+)-erogorgiaene through a kinetic enantiodifferentiating step
Davies, Huw M. L.,Walji, Abbas M.
, p. 1733 - 1735 (2007/10/03)
(Chemical Equation Presented) The combined approach of C-H activation and a Cope rearrangement catalyzed by a rhodium catalyst [Rh2(R-dosp) 4] (dosp = (N-dodecylbenzenesulfonyl)prolinate) is shown to be a very effective method for the construction of the three stereogenic centers (marked in red, see scheme) present in the diterpene erogorgiaene (1).
Enantioselective Total Syntheses and Stereochemical Studies of All Four Stereoisomers of Yingzhaosu C
Xu, Xing-Xiang,Dong, Han-Qing
, p. 3039 - 3044 (2007/10/02)
The enantioselective total syntheses and the stereochemistry of all four stereoisomers of yingzhaosu C, an antimalarial peroxy-containing sesquiterpene isolated from yingzhao , are described.The key to the syntheses was th
