Selective Synthesis of Dihydrophenanthridine and Phenanthridine Derivatives from the Cascade Reactions of <i>o</i>-Arylanilines with Alkynoates through C–H/N–H/C–C Bond Cleavage
作者:Yuanshuang Xu、Caiyun Yu、Xinying Zhang、Xuesen Fan
DOI:10.1021/acs.joc.1c00256
日期:2021.4.16
unprecedented selective synthesis of dihydrophenanthridine and phenanthridinederivatives through the cascade reactions of 2-arylanilines with alkynoates is presented. Mechanistic studies showed that the formation of the dihydrophenanthridine scaffold involves an initial C(sp2)–H alkenylation of 2-arylaniline with alkynoate followed by an intramolecular aza-Michael addition. When this reaction is carried out
Nickel-catalyzed regioselective carbocyclization of ortho-halophenyl ketones with propiolates: an efficient route to disubstituted indenolsElectronic supplementary information (ESI) available: synthesis and characterization of compounds 3. See http://www.rsc.org/suppdata/cc/b2/b201473d/
作者:Dinesh Kumar Rayabarapu、Chien-Hong Cheng
DOI:10.1039/b201473d
日期:2002.4.19
Carbocylization of o-halophenyl ketones with propiolates in the presence of Ni(dppe)Br2 and Zn powder in acetonitrile at 80 °C afforded the corresponding 2,3-disubstituted indenols.
Synthesis of Seven-membered Lactones via Nickel- and Zinc-Catalyzed Highly Regio- and Stereoselective Cyclization of 2-Iodobenzyl Alcohols with Propiolates
作者:Dinesh Kumar Rayabarapu、Chien-Hong Cheng
DOI:10.1021/ja017390p
日期:2002.5.1
class of substituted seven-membered lactones 3 were conveniently synthesized viacyclization of o-iodobenzyl alcohol 1 (o-IC(6)H(4)CH(2)OH) with various propiolates 2 (RC triple bond CCOOMe) in the presence of Ni(dppe)Br(2) and Zn powder in acetonitrile at 80 degrees C. The catalytic reaction is highly regio- and stereoselective affording seven-membered lactones in moderate to good yields. This methodology
Novel Isomerically Pure Tetrasubstituted Allylboronates: Stereocontrolled Synthesis of α-Exomethylene γ-Lactones as Aldol-Like Adducts with a Stereogenic Quaternary Carbon Center
作者:Jason W. J. Kennedy、Dennis G. Hall
DOI:10.1021/ja016391e
日期:2002.2.1
1-alkoxycarbonyl vinylcopper(I) intermediates from the conjugate addition of organocuprates onto acetylenic esters were trapped with very high cis-addition selectivity with iodomethylboronic esters in the presence of HMPA. The resulting isomerically pure 3,3-disubstituted allylboronates react with aldehydes in a highly diastereo- and enantioselective manner, providing α-exomethylene γ-lactones with a stereogenic
Lewis Acid Catalyzed Allylboration: Discovery, Optimization, and Application to the Formation of Stereogenic Quaternary Carbon Centers
作者:Jason W. J. Kennedy、Dennis G. Hall
DOI:10.1021/jo049773m
日期:2004.6.1
A full account of the development of the first catalytic manifold for the additions of allylboronates to aldehydes is described. The thermal additions (both diastereospecific and enantioselective) of 2-carboxyester 3,3-disubstituted allylboronates 1 to both aromatic and aliphatic aldehydes give biologically and synthetically important exo-methylene butyrolactones 2 containing a β-quaternary carbon