A facile and efficient approach for the synthesis of spirooxindoles has been developed via the coupling of spirocyclic C, C-palladacycles with CH2Br2. The key spirocyclic palladacycles are generated catalytically via intramolecular remote C–H activation. A range of spirooxindoles can be synthesized in good to excellent yields from readily available starting materials.
A RhIII‐catalyzed intramolecularoxidative cross‐coupling between double bonds for the synthesis of macrolides is described. Under the optimized reaction conditions, macrocycles containing a diene moiety can be formed in reasonable yields and with excellent chemo‐ and stereoselectivity. This method provides an efficient approach to synthesize macrocyclic compounds containing a 1,3‐conjugated diene
A highly efficient palladium‐catalyzed disilylation reaction of arylhalides through C−H activation has been developed for the first time. The reaction has broad substrate scope. A variety of arylhalides can be disilylated by three types of C−H activation, including C(sp2)−H, C(sp3)−H, and remote C−H activation. In particular, the reactions are also unusually efficient. The yields are essentially
Water as a Hydride Source in Palladium-Catalyzed Enantioselective Reductive Heck Reactions
作者:Wangqing Kong、Qian Wang、Jieping Zhu
DOI:10.1002/anie.201700195
日期:2017.3.27
Pd‐catalyzed intramolecular asymmetric carbopalladation of N‐aryl acrylamides followed by reduction of C(sp3)‐Pd intermediate using diboron–water as a hydride source afforded enantioenriched 3,3‐disubstituted oxindoles in high yields and enantioselectivities. When heavy water was used as a deuterium donor in combination with bis(catecholato)diboron (Cat2B2), deuterium was incorporated into the products
N芳基丙烯酰胺在Pd催化下的分子内不对称碳环合钯,然后使用乙硼酸水作为氢化物源还原C(sp 3)-Pd中间体,从而以高收率和对映选择性提供了对映体富集的3,3-二取代的吲哚。当重水与双(邻苯二酚)二硼(Cat 2 B 2)一起用作氘供体时,氘以高合成效率掺入产品中。配体决定了反应的对映选择性和反应路径,从而提供了氢芳基化(还原性Heck)或碳硼化产物。
Pd-Catalyzed Spirocyclization via C–H Activation and Benzyne Insertion
spirocyclization forming spirooxindoles and spirodihydrobenzofurans has been achieved. Mechanistic studies suggest that the transformation proceeds through sequential carbopalladation, C–Hactivation, and benzyne insertion. Both classes of spirocycles have been synthesized in good to excellent yields, and the procedure is readily scalable.