The “two-fold reaction” benchmark applied to the copper catalyzed assembling of 1ω-difunctional hydrocarbon chains

A Homologous Series of O‐ and N‐Functionalized 2,2‐Difluoro1,3‐benzodioxoles: an Exercise in Organometallic Methodology

“…A chain length of three methylene units does not set limits for the accessibility of ψ‐(2,2‐difluoro‐1,3‐benzodioxol‐4‐yl)alkanols. To prepare higher homologs one has simply to replace oxirane or oxetane by suitably acetalprotected ψ‐haloalkanols 16. Thus, 1‐iodo‐4‐(methoxymethoxy)butane was smoothly condensed with the 4‐lithiated 2,2‐difluoro‐1,3‐benzodioxole to afford, after deprotonation with acid, the alcohol 2e in 18% yield.…”

Bis-imidazoles as molecular probes for peripheral sites of the zinc endopeptidase of botulinum neurotoxin serotype A

“…Bis-imidazoles 2a-h were readily prepared according to Scheme 1 by coupling two imidazoles in the salt form with dibromoalkanes 4 or linkers [19][20][21][22][23][24][25][26][27][28][29] obtained from tosylation of alkyldiols 5 or bromoalcohols 7. Bis-imidazoles 3a-h were made in good yields by activating 1H-imidazole-5-carboxylic acid 9 with N-hydroxysuccinimide and coupling 9 with a,x-alkyldiamines via amidation (Scheme 2).…”

Studies on the Synthesis of Macrocyclic Allenes by Ring Closing Metathesis and Doering–Moore–Skattebøl Reaction

“…To a solution of hexadeca-1,15-diene [22] (10.2 g, 45.9 mmol) in CH 2 Cl 2 (40 mL) was added CHBr 3 (41.4 g, 0.17 mol), triethylbenzylammonium chloride (1.10 g, 4.8 mmol) and 50 % aqueous NaOH (30 mL). The mixture was stirred for 8 h with an Ultra Turrax stirrer and then diluted with pentane (300 mL) and brine (250 mL).…”

“…To a refluxing solution of 16 (110 mg, 0.20 mmol) in CH 2 Cl 2 (100 mL) was added benzylidenedichlorobis(tricyclohexylphosphanyl)ruthenium (25 mg, 0.03 mmol), and refluxing was continued for 3 h. After cooling to room temperature, cyclohexane (50 mL) was added, the solvent was removed under reduced pressure and the crude product was purified by flash chromatography (cyclohexane/ethyl acetate, 20:1) to give 90 mg (85 %) of 17 (2:1 mixture of E/Z isomers) as a colorless oil. 1 Octadeca-1,2,16,17-tetraene (18): To a solution of hexadeca-1,15diene [22] (10.2 g, 45.9 mmol) in CH 2 Cl 2 (40 mL) was added CHBr 3 (41.4 g, 0.17 mol), triethylbenzylammonium chloride (1.10 g, 4.8 mmol) and 50 % aqueous NaOH (30 mL). The mixture was stirred for 8 h with an Ultra Turrax stirrer and then diluted with pentane (300 mL) and brine (250 mL).…”

“…According to the preparation of 18, octadeca-1,17-diene [22] (11.0 g, 43.9 mmol) in CH 2 Cl 2 (40 mL) was treated with CHBr 3 (33.4 g, 0.13 mol), triethylbenzylammonium chloride (1.05 g, 4.6 mmol) and 50 % aqueous NaOH (50 mL). Yield: 21.9 g (84 %) of the α,ω-bis(dibromocyclopropane) as a pale yellow solid (m.p.…”