accessible tertiary propargyl vinyl ethers as substrates and imidazole as a catalyst to form up to two new rings, three new C−C bonds, six stereogenic centers and one transannular oxo‐bridge. The manifold is efficient, scalable and instrumentally simple to perform and entails a propargyl Claisen rearrangement–[1,3]H shift, an oxa‐6π‐electrocyclization, and an intramolecularDiels–Alderreaction.
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。
Atom Efficient Synthesis of Selectively Difluorinated Carbocycles through a Gold(I)-Catalyzed Cyclization
作者:Adam W. McCarter、Magdalena Sommer、Jonathan M. Percy、Craig Jamieson、Alan R. Kennedy、David J. Hirst
DOI:10.1021/acs.joc.8b01121
日期:2018.8.17
Difluorinated enol acetals bearing a pendant alkene group can be cyclized and reduced in one pot to form fluorinated diol motifs. Alternatively, the cyclization of terminal alkynes allows for the synthesis of fluorinated pyran scaffolds. Both cyclization processes can be performed under mild conditions allowing access to complex products rich in functionality. The cyclic systems are synthesized concisely