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。
Synthesis of C2-Symmetric Benzimidazolium Salts and Their Application in Palladium-Catalyzed Enantioselective Intramolecular α-Arylation of Amides
作者:Weiping He、Wei Zhao、Bihui Zhou、Haifeng Liu、Xiangrong Li、Linlin Li、Jie Li、Jianyou Shi
DOI:10.3390/molecules21060742
日期:——
A series of C₂-symmetric chiral benzimidazoliumsalts, the precursor of N-heterocycliccarbeneligands, were designed and synthesized from 1,2-dibromobenzene. In situ prepared corresponding carbenes were tested in the asymmetric palladium-catalyzed intramolecular α-arylation of amides, affording chiral diarylmethanols with high yields and moderate enantioselectivities.
Matching the Chirality of Monodentate N-Heterocyclic Carbene Ligands: A Case Study on Well-Defined Palladium Complexes for the Asymmetric α-Arylation of Amides
N-Heterocyclic carbeneligands derived from C(2)-symmetric diamines with naphthyl side chains are introduced as chiral monodentate ligands, and their palladium complexes (NHC)Pd(cin)Cl are prepared. These compounds exist as a mixture of diastereomers, and the palladium complexes can be successfully separated and their absolute stereochemistry assigned. When used in the asymmetricintramolecular alpha-arylation