Metal-Free Synthesis of <i>N</i>-Aryl-Substituted Azacycles from Cyclic Ethers Using POCl<sub>3</sub>
作者:Minh Thanh La、Soosung Kang、Hee-Kwon Kim
DOI:10.1021/acs.joc.9b00377
日期:2019.6.7
A facile method for the synthesis of N-aryl-substituted azacycles from arylamines and cyclic ethers has been developed. In this study, arylamines were treated with cyclic ethers in the presence of POCl3 and DBU to provide five- and six-membered azacycles. Using this method, various azacycloalkanes, isoindolines, and tetrahydroisoquinolines were prepared in high yields. This synthetic method offers
Phosphoryl chloride-mediated solvent-free synthesis of N-aryl-substituted azacycles from arylamines and cyclic ethers
作者:Van Hieu Tran、Minh Thanh La、Hee-Kwon Kim
DOI:10.1016/j.tetlet.2019.06.019
日期:2019.7
cyclic ethers is described. In this method, the combination of POCl3 and DBU is crucial for conversion of arylamines and cyclic ethers to five- and six-membered azacycles. Without solvent, a variety of N-aryl-substituted, five-membered azacycles (pyrrolidines, 2-methylpyrrolidines, and piperidine) and six-membered azacycles (isoindolines and tetrahydroisoquinolines) are synthesized in high yields. This
Dual C(sp<sup>3</sup>
)−H Bond Functionalization of N-Heterocycles through Sequential Visible-Light Photocatalyzed Dehydrogenation/[2+2] Cycloaddition Reactions
through a sequential visible‐light photocatalyzed dehydrogenation/[2+2] cycloaddition procedure. As a complementary approach to the well‐established use of iminium ion and α‐amino radical intermediates, the elusive cyclic enamine intermediates were effectively generated by photoredox catalysis under mild conditions and efficiently captured by acetylene esters to form a wide array of bicyclic amino acid
Photoinduced C(sp3)–H phosphorylation was reported to rapidly install a phosphoryl group on the biologically useful saturated aza-heterocycles with commercially available diarylphosphine oxide reagents by a novel organic photocatalyst.
The construction of the pyrrolidine ring about a nitrogen of a primary amine by a reductive condensation reaction using 2,5-dimethoxytetrahydrofuran and sodium borohydride in acidic water medium is described. The reaction is fast, affords good to excellent yields and appears insensitive to electron effects and severe steric hindrance; it is found to be compatible with a large variety of aryl substituents, including nitro and oxo groups. The reaction allows the introduction of two deuterium atoms, with label conservation, in both the α-positions of the pyrrolidine ring by the use of sodium borodeuteride instead of sodium borohydride.