Chiral α-Amino Acid/Palladium-Catalyzed Asymmetric Allylation of α-Branched β-Ketoesters with Allylic Amines: Highly Enantioselective Construction of All-Carbon Quaternary Stereocenters
作者:Ya-Nan Xu、Meng-Zeng Zhu、Shi-Kai Tian
DOI:10.1021/acs.joc.9b02282
日期:2019.11.15
use of allylic amines as allylating agents in the chiral α-aminoacid/palladium-catalyzed asymmetric allylation of α-branched β-ketoesters, providing highly enantioselective access to all-carbon quaternary stereocenters. Notably, the formation of a primary amine, a secondary amine, or ammonia as a byproduct has little influence on the enantioselectivity for the catalytic asymmetric synthesis of structurally
A Cu-catalyzed regio- and enantioselective hydroboration of various naphthylallylic compounds affording chiral boronates with high yields and excellent enantioselectivities (up to 96% ee) was presented. The utility of the boronated products is further illustrated by other stereospecific C–B bond transformations to produce amino alcohols and other useful compounds.
Synthesis of Diverse Boron-Handled N-Heterocycles via Radical Borylative Cyclization of <i>N</i>-Allylcyanamides
作者:Ji-Kang Jin、Feng-Lian Zhang、Qiang Zhao、Jun-An Lu、Yi-Feng Wang
DOI:10.1021/acs.orglett.8b03303
日期:2018.12.7
A synthetic method based on radical borylation/cyclization cascades of N-allylcyanamides was developed to construct diverse boron-substituted N-heterocycles. In the reaction process, the N-heterocyclic carbene-boryl radical underwent a chemo- and regioselective addition to the alkene moiety, followed by cyclization with the N-cyano group. The resulting amide-iminyl radical intermediates underwent further reactions to afford various boron-tethered N-heterocyclic molecules. Further transformations to access synthetically useful building blocks were also demonstrated.