Hydrogen-Bond-Activated Palladium-Catalyzed Allylic Alkylation via Allylic Alkyl Ethers: Challenging Leaving Groups
摘要:
C-O bond cleavage of allylic alkyl ether was realized in a Pd-catalyzed hydrogen-bond-activated allylic alkylation using only alcohol solvents. This procedure does not require any additives and proceeds with high regioselectivity. The applicability of this transformation to a variety of functionalized allylic ether substrates was also investigated. Furthermore, this methodology can be easily extended to the asymmetric synthesis of enantiopure products (99% ee).
Palladium-Catalyzed Allylic Alkylation of Simple Ketones with Allylic Alcohols and Its Mechanistic Study
作者:Xiaohong Huo、Guoqiang Yang、Delong Liu、Yangang Liu、Ilya D. Gridnev、Wanbin Zhang
DOI:10.1002/anie.201403410
日期:2014.6.23
Allylicalcohols were directly used in Pd‐catalyzed allylicalkylations of simpleketones under mild reaction conditions. The reaction proceeded smoothly at 20 °C by the concerted action of a Pd catalyst, a pyrrolidine co‐catalyst, and a hydrogen‐bonding solvent, and does not require any additional reagents. A computational study suggested that methanol plays a crucial role in the formation of the
Hydrogen-bond-activated C-N bond cleavage of allylic amines was realized in Pd-catalyzed allylic alkylation to form the C-C bond product. The method could be expanded to a series of allylic amines and carbonyl compounds with excellent results. It provides a new and convenient access to C-C bond formation based on Pd-catalyzed allylic alkylation of allylic amines by using only inexpensive alcohol solvents.
烯丙胺的氢键活化 CN 键断裂是在 Pd 催化的烯丙基烷基化中实现的,以形成 CC 键产物。该方法可以扩展到一系列烯丙基胺和羰基化合物,并取得了优异的结果。它通过仅使用廉价的醇溶剂,为基于 Pd 催化的烯丙基胺的烯丙基烷基化形成 CC 键提供了一种新的便捷途径。
Chiral Hydroxytetraphenylene-Catalyzed Asymmetric Conjugate Addition of Boronic Acids to Enones
作者:Guo-Li Chai、A-Qiang Sun、Dong Zhai、Juan Wang、Wei-Qiao Deng、Henry N. C. Wong、Junbiao Chang
DOI:10.1021/acs.orglett.9b01637
日期:2019.7.5
(S)-2,15-Br2-DHTP-catalyzed asymmetric conjugate addition of boronic acids to β-trifluoromethyl α,β-unsaturated ketones and enones was studied. The reaction afforded the corresponding Michael addition products in moderate to high yields with excellent enantioselectivities (up to 99:1 er). This catalytic system features mild reaction conditions, high efficiency, and tolerance to heteroarylboronic acids
catalysts has been proven to have great advantages in asymmetric catalysis. We constructed two chiral metalla-triangles by highly efficient coordination-driven self-assembly from a chiral 3,3'-dipyridyl substituted BINOL donor. They were successfully applied in asymmetric conjugate addition of a series of α,β-unsaturated ketones with trans-styrylboronic acids. The use of these metalla-triangles as supramolecular