as natural products, pharmaceuticals, and π-conjugated systems are at the heart of constructing and modifying organic molecules, whereby the selectivity and predictability are of the utmost importance. Herein, we report the highly C3-selective C–H borylation of strychnine along with olefin isomerization, catalyzed by an iridium complex with a diphosphine ligand. This method enabled us to rapidly produce
2,6-Dicarboxypyridinium Chlorochromate. An Efficient and Selective Reagent for the Mild Deprotection of Acetals, Thioacetals, and 1,1-Diacetates to Carbonyl Compounds
chlorochromate (2,6- DCPCC ) was found to be an efficientreagent for the conversion of acetals, thioacetals, and 1,1-diacetates to their corresponding carbonyl compounds under neutral and anhydrous conditions in good to excellent yields. Selectivedeprotection of acetals or 1,1-diacetates in the presence of thioacetals at room temperature is also observed with this reagent.
Selective, Convenient and Efficient Deprotection of Trimethylsilyl and Tetrahydropyranyl Ethers, Ethylene Acetals and Ketals with Oxone under Non-aqueous Conditions
An efficient and selective method for the deprotection of trimethylsilyl (TMS) and tetrahydropyranyl (THP) ethers, ethylene acetals and ketals to their corresponding alcohols and carbonyl compounds using oxone in refluxing acetonitrile is described. Excellent chemoselectivity of this method makes it a useful and practical procedure in organic synthesis.
A mild and efficient method for selective cleavage of ketals and acetals using lithium chloride in water - dimethyl sulfoxide
作者:Pijus Kumar Mandal、Pinak Dutta、Subhas Chandra Roy
DOI:10.1016/s0040-4039(97)01689-4
日期:1997.10
A mild and efficient neutral aqueous method for selective cleavage of acetals and ketals to the corresponding carbonyl compounds has been established by using LiCl in H2O-DMSO at elevated temperature. While aryl and α,β-unsaturated ketals and acetals underwent smooth cleavage, diaryl, non-aryl and isolated ketals and acetals remained unaffected under the reaction conditions.
Chemoselective (Trans)thioacetalization of Carbonyl Compounds with a Reusable Lewis Acid-Surfactant-Combined Copper Bis(dodecyl sulfate) Catalyst in Water
A Lewis acid-surfactant-combined copper bis(dodecyl sulfate) [Cu(DS)2] catalyst served as an efficient and reusable catalyst for the thioacetalization and transthioacetalization of carbonyl compounds and O,O-acetals in water at room temperature. Some of the major advantages of this procedure are high chemoselectivity, ease of operation and purification without any organic solvent, and high yields.