Highly Diastereoselective Gold- or Copper-Catalyzed Formal [4+3] Cycloaddition of 1-(1-Alkynyl) Cyclopropyl Ketones and Nitrones
作者:Yu Bai、Jie Fang、Jun Ren、Zhongwen Wang
DOI:10.1002/chem.200901133
日期:2009.9.14
Domino day: A highlydiastereoselective Cu‐ or Au‐catalyzed tandem cycloisomerization/formal [4+3] cycloaddition of 1‐(1‐alkynyl) cyclopropylketones and nitrones has been developed (see scheme) along with an efficient one‐pot, three‐component version of this reaction. This methodology provides a route to a new type of 5/7‐bicyclic heterocycle: a furan‐fused oxazepine.
Chemoselective synthesis of highly substituted 1,2-allenyl ketones, furans, and 2-alkynyl ketones from reaction of lithium selenolates with 1-(1-alkynyl)cyclopropyl ketones and electrophiles
作者:Jianfeng Xu、Shugao Zhu、Luling Wu、Xian Huang
DOI:10.1039/c2ob25071c
日期:——
A homo-Michael addition reaction of lithium selenolates with 1-(1-alkynyl)cyclopropyl ketones and the subsequent reaction with electrophiles such as PhSeBr, NFSI and NCS is reported. Based on the nature of electrophiles, this reaction may afford highly substituted 1,2-allenyl ketones or furans (E+ = PhSe+) and 2-alkynyl ketones (E+ = F+, Cl+, active halides) as the final products, respectively.
Unexpected Formation of (<i>E</i>)-4-Alkene 1,3-Diketones from the Three-Component Reaction of Lithium Selenolates with 1-(1-Alkynyl)cyclopropyl Ketones and Aldehydes
作者:Jianfeng Xu、Luling Wu、Xian Huang
DOI:10.1021/jo2005439
日期:2011.7.15
A novel three-component stereoselective synthesis of (E)-4-alkene 1,3-diketones from lithium selenolates, 1-(1-alkynyl)cyclopropylketones, and aldehydes is reported. This reaction afforded the products in moderate to good yields with the formation of a new C–Se single bond, a new C–C double bond, and a new C–O double bond.
Highly Efficient Synthesis of Multisubstituted Furans through Cupric Halide-Mediated Intramolecular Halocyclization of 1-(1-Alkynyl)cyclopropyl Ketones
作者:Mei Zhu、Wei-Jun Fu、Chen Xu、Guang-Long Zou、Zhi-Qiang Wang、Bao-Ming Ji
DOI:10.1002/ejoc.201200601
日期:2012.8
A convenient and efficient method for the synthesis of 3-halofurans was developed by using a cascade reaction between 1-(1-alkynyl)cyclopropyl ketones and cupric halide. Under mild reaction conditions, both 3-chloro- and 3-bromofuran derivatives were obtained in high yields. The reaction involves consecutive multiple bond formations, includingC–O and C–Br bonds, with high regioselectivity. Mechanistic