4170-71-2Relevant articles and documents
Synthesis of allenylzinc reagents by 1,2-rearrangement of alkynyl(disilyl)zincates derived from acetylenic epoxides and acetylenic aziridines
Bochatay, Valentin N.,Debien, Laurent,Chemla, Fabrice,Ferreira, Franck,Jackowski, Olivier,Perez-Luna, Alejandro
, p. 609 - 616 (2017)
Lithium alkynyl(disilyl)zincates obtained from metalated ethynyloxiranes, as well as from N-tert-butanesulfinyl(ethynyl)aziridines or N-tert-butanesulfonyl(ethynyl)aziridines, undergo 1,2-migration of the organosilyl group with ring opening of the oxirane or aziridine ring by SNi displacement. A developed protocol that involves nBuLi for the metalation step offers a straightforward approach to the corresponding δ-oxy- and δ-amino α-silyl allenylzinc intermediates. The reagents derived from the epoxides are amenable to subsequent in situ condensation with aldehydes or ketones to provide 1,3-diols but not those derived from aziridines that only react sluggishly in similar condensations.
Chiral Br?nsted-Acid-Catalyzed Asymmetric Oxidation of Sulfenamide by Using H2O2: A Versatile Access to Sulfinamide and Sulfoxide with High Enantioselectivity
Ma, Long-Jun,Chen, Shu-Sen,Li, Guang-Xun,Zhu, Jin,Wang, Qi-Wei,Tang, Zhuo
, p. 1525 - 1530 (2019/02/01)
Herein, we describe an example of catalytic asymmetric synthesis of sulfinamides. Aromatic sulfenamides were chosen as useful substrates, because of the indispensable N-H bond, which could form an efficient hydrogen bond with chiral phosphoric acid. Hsub
Stereoselective synthesis of isoindolinones and tert-butyl sulfoxides
Kaw?cki, Robert,Stańczyk, Wojciech,Jaglińska, Agnieszka
, p. 578 - 584 (2017/12/28)
A reaction of Grignard reagents with an optically pure N-sulfinylimine derived from methyl 2-formylbenzoate yields enantioenriched isoindolinones and tert-butyl sulfoxides. The products are formed by the addition of the nucleophile to N-sulfinylimine followed by cyclization to form N-tert-butylsulfinylisoindolinone, which readily undergoes substitution with a second equivalent of Grignard reagent. The reaction can be carried out in dichloromethane at room temperature or at elevated temperatures without any loss of stereoselectivity. The use of nucleophiles other than Grignard reagents has also been investigated.
Multivariate Metal-Organic Frameworks as Multifunctional Heterogeneous Asymmetric Catalysts for Sequential Reactions
Xia, Qingchun,Li, Zijian,Tan, Chunxia,Liu, Yan,Gong, Wei,Cui, Yong
supporting information, p. 8259 - 8266 (2017/06/28)
The search for versatile heterogeneous catalysts with multiple active sites for broad asymmetric transformations has long been of great interest, but it remains a formidable synthetic challenge. Here we demonstrate that multivariate metal-organic frameworks (MTV-MOFs) can be used as an excellent platform to engineer heterogeneous catalysts featuring multiple and cooperative active sites. An isostructural series of 2-fold interpenetrated MTV-MOFs that contain up to three different chiral metallosalen catalysts was constructed and used as efficient and recyclable heterogeneous catalysts for a variety of asymmetric sequential alkene epoxidation/epoxide ring-opening reactions. Interpenetration of the frameworks brings metallosalen units adjacent to each other, allowing cooperative activation, which results in improved efficiency and enantioselectivity over the sum of the individual parts. The fact that manipulation of molecular catalysts in MTV-MOFs can control the activities and selectivities would facilitate the design of novel multifunctional materials for enantioselective processes.
