title: Grignard reagent/CuI/LiCl-mediated stereoselective cascade addition/cyclization of diynes: a novel pathway for the construction of 1-methyleneindene derivatives.
abstract: Diynes containing a cyclopropane group smoothly undergo a novel intramolecular and stereoselective cascade addition/cyclization reaction to produce the corresponding 1-methyleneindene derivatives in moderate to good yields. This interesting transformation is mediated by Grignard reagent/CuI with LiCl as an additive under mild conditions. The obtained product can easily be further functionalized through cyclopropyl ring opening. A plausible reaction mechanism has also been presented on the basis of deuterium labeling and control experiments.
authors.affiliation: State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Ling-Ling Lu, Shanghai, 200032 (P. R. China), Fax: (+86) 21-64166128.
authors.forename: De-Yao
authors.initials: DY
authors.lastname: Li
authors.forename: Yin
authors.initials: Y
authors.lastname: Wei
authors.forename: Min
authors.initials: M
authors.lastname: Shi
mesh_terms: D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D003500:Cyclization; D003521:Cyclopropanes / Q000737:chemistry*; D053280:Diynes / Q000737:chemistry*; D007202:Indicators and Reagents / Q000737:chemistry*; D018021:Lithium Chloride / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D003521:Cyclopropanes; D053280:Diynes; D007202:Indicators and Reagents; D003300:Copper; D018021:Lithium Chloride
keywords: Grignard reaction; alkenes; alkynes; carbocycles; cyclization; small ring systems