Iron-Catalyzed Ring Expansion of Cyclobutanols for the Synthesis of 1-Pyrrolines by Using MsONH<sub>3</sub>OTf
作者:Daijiao Zhuang、Tharcisse Gatera、Zhenyu An、Rulong Yan
DOI:10.1021/acs.orglett.1c04304
日期:2022.1.21
The synthesis of 1-pyrrolinesfrom cyclobutanol derivatives and an aminating reagent (MsONH3OTf) has been developed. This one-pot procedure achieves C–N bond/C═N bond formation via ring expansion. A series of 1-pyrroline derivatives are synthesized in moderate to good yields under mild conditions.
We herein report an efficient and systematic synthesis of 1-pyrrolines from cyclobutyl azides under thermal and neutral conditions. The reaction proceeded without any additional reagents, and nitrogen was generated as the sole by-product. Furthermore, the generated 1-pyrrolines could be continuously transformed into pyrroles, N-Boc-amines, and oxaziridines in an one-pot manner.
Enantioselective Imine Reduction Catalyzed by Phosphenium Ions
作者:Travis Lundrigan、Erin N. Welsh、Toren Hynes、Chieh-Hung Tien、Matt R. Adams、Kayelani R. Roy、Katherine N. Robertson、Alexander W. H. Speed
DOI:10.1021/jacs.9b07293
日期:2019.9.11
The first use of phosphenium cations in asymmetric catalysis is reported. A diazaphosphenium triflate, prepared in two or three steps on a multi-gram scale from commercially available materials catalyzes the hydroboration or hydrosilation of cyclic imines with enantiomeric ratios of up to 97:3. Catalyst loadings are as low as 0.2 mole percent. Twenty-two aryl/heteroaryl pyrrolidines and piperidines