Enynylation of 2-Iodo-4-(phenylchalcogenyl)-1-butenes via Intramolecular Chelation: Approach to the Synthesis of Conjugated Dienynes or Trienynes
作者:Min Shi、Le-Ping Liu、Jie Tang
DOI:10.1021/ol051101a
日期:2005.7.1
[reaction: see text] 2-Iodo-4-(phenylchalcogenyl)-1-butenes 3 and 4, which are derived from methylenecyclopropanes 1, can be enynylated with alkynes catalyzed by Pd(OAc)(2) to give conjugateddienynes 5 and 6 in the absence of any phosphine ligand and copper salt, and trienyne 9a can be obtained by oxidation of compound 5a. A plausible reaction mechanism has been proposed.
<i>N</i>-Bromosuccinimide and Lithium Bromide: An Efficient Combination for the Dibromination of Carbon-Carbon Unsaturated Bonds
作者:Min Shi、Li-Xiong Shao
DOI:10.1055/s-2006-941558
日期:——
Compounds possessing unsaturated bonds such as alkenes, alkynes, allenes, and methylenecyclopropanes (MCPs) can be dibrominated within minutes by NBS and lithium bromide in THF at room temperature in good to excellent yields under mild conditions.
Ring-Expansion of MCPs in the Presence of DIAD or DEAD and Lewis Acids
作者:Li-Xiong Shao、Min Shi
DOI:10.1002/ejoc.200300515
日期:2004.1
Treatment of methylenecyclopropanes (MCPs) with DIAD or DEAD in MeCN under mild conditions in the presence of Lewisacid Zr(OTf)(4) gave the cyclobutanone ring-expansion products in good to high yields based on the employed DIAD or DEAD. From a deuterium labeling experiment, the oxygen atom is derived from ambient water. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).
Manganese(III)-Mediated Oxidative Annulation of Methylenecyclopropanes with 1,3-Dicarbonyl Compounds
作者:Jin-Wen Huang、Min Shi
DOI:10.1021/jo050181t
日期:2005.5.1
Manganese(III)-mediated oxidative annulation of methylenecyclopropanes with 1,3-dicarbonyl compounds in acetic acid produces 4,5-dihydrofuran derivatives as [3+2] annulation products in moderate to good yields under mild conditions. The possible reaction mechanism is discussed on the basis of previous mechanistic investigation.