Stereoselective Synthesis of Vinyl Ethers by the Reaction of N-(Arylidene(or alkylidene)amino)-2-azetidinones with Ozone
摘要:
Ozonolysis of N-(arylidene(or alkylidene)amino)-2-azetidinones followed by NaBH4 workup yields enol ethers in good yields with high levels of stereoselectivity. Di- and trisubstituted olefin derivatives are available through this procedure. Chiral 2-azetidinones lead to enol ethers with a chiral moiety without racemization. The reaction is thought to occur through a novel B-type fragmentation of the 2-azetidinone ring. This process is closely related to the well-known N-nitrosoamide to ester rearrangement and the decarboxylation of oxetan-2-ones.
Stereoselective Synthesis of Vinylboronates by Rh‐Catalyzed Borylation of Stereoisomeric Mixtures
作者:Shenhuan Li、Jie Li、Tianlai Xia、Wanxiang Zhao
DOI:10.1002/cjoc.201800575
日期:2019.5
The stereoselective preparation of vinylboronates via rhodium‐catalyzed borylation of E/Z mixtures of vinyl actetates is described, and this method was also extended to synthesis of vinyldiboronates. These transformations feature high functional group compatibility and mild reaction conditions. Control experiments support a mechanism that involved a Rh‐catalyzed borylation‐isomerization sequence. The
Carboxylic acid addition to terminal alkynes utilizing ammonium tagged Hoveyda-Grubbs catalyst supported on magnetically separable core/shell silica: A highly reusable and air compatible catalytic system
作者:Bengi Özgün Öztürk、Didar Gürcü、Solmaz Karabulut Şehitoğlu
DOI:10.1016/j.jorganchem.2019.01.005
日期:2019.3
core/shell silica gel was tested on carboxylicacid addition reactions to terminal alkynes using a variety of carboxylicacidderivatives under air atmosphere. The catalytic system was found to be compatible with air atmosphere and can tolerate even non-degassed solvents. The reaction parameters such as temperature, substrate/catalyst ratio and the effect of carboxylicacid on the selectivity and yield of
Palladium catalysed β-selective oxidative Heck reaction of an electron-rich olefin
作者:Lingkui Meng、Chao Liu、Wei Zhang、Chao Zhou、Aiwen Lei
DOI:10.1039/c3cc47045h
日期:——
A palladium catalysed oxidative beta-arylation of an electron-richolefin is described. The reaction was under mild conditions; meanwhile, additives and directing groups are not needed. Various arylboronic acids worked well under the standard conditions.