Zirconium-catalyzed and zirconium-promoted cyclization reactions of non-conjugated dienes with alkylmagnesium halides to give cycloalkylmethylmagnesium derivatives

Transition‐Metal‐Catalyzed Sequential Cross‐Coupling of Bis(iodozincio)methane and ‐ethane with Two Different Organic Halides

“…1‐Phenyl‐1,6‐heptadiene (6) :21 Cinnamyl chloride (1.0 mmol in THF, 1.0 mL) and 1 (0.5 M solution in THF, 2 mL, 1.0 mmol) were added to a solution of [Pd 2 (dba) 3 ]⋅CHCl 3 (26 mg, 0.025 mmol) and 3 c (0.1 mmol) in THF (1.0 mL), and the mixture was stirred at room temperature for 30 min. After this time, allyl bromide (1.5 mmol in THF 1.0 mL) was added to the mixture at room temperature.…”

Tandem Insertion of Halocarbenoids and Lithium Acetylides into Zirconacycles: A Novel Rearrangement to Zirconium Alkenylidenates by β‐Addition to an Alkynyl Zirconocene

“…Zirconocene-mediated co-cyclisation of 1,7-octadiene provided cyclohexyl-fused zirconacycle 81 as an 82:18 mixture of cis:trans ring junction isomers, as determined by hydrolysis of a sample to provide cis-and trans-1,2-dimethylcyclohexane. [32] Insertion of lithiated 1,1-dibromoheptane followed by lithium phenylacetylide gave compound 83 as an inseparable mixture of cis:trans ring junction isomers in the ratio of 2:1 and 53 % combined yield. The stereochemistry of cis-83 followed from the symmetry demonstrated by 13 C NMR spectroscopy, the number of signals for the core carbons being halved.…”

Catalytic cyclometalation reaction of unsaturated compounds in synthesis of magnesa- and aluminacarbocycles

“…Transmetalation of bimetallic complexes (165) with starting organomagnesium reagent in catalytic cycle is the key step, which determines chemoselectivity of the reaction [214,215]. In order to clarify the mechanism of the above transformations Negishi and co-workers have studied the interaction between BuMgCl or Bu 2 Mg and 3-bis(g 5 -cyclopentadienyl)zirconabicyclo[3.3.0]octane 164a as the probable intermediate in the catalyzed by Cp 2 ZrCl 2 reaction of hepta-1,5-diene with BuMgX (X = Cl, Bu) in different solvents [216]. The authors concluded that the reaction of 164a with Bu n MgCl in THF afforded monomagnesium derivative 163.…”