Diastereo- and Enantioselective Carbolithiation of Allyl <i>o</i>-Lithioaryl Ethers. New Chiral Cyclopropane Derivatives
作者:José Barluenga、Francisco J. Fañanás、Roberto Sanz、César Marcos
DOI:10.1021/ol026078x
日期:2002.6.1
[reaction: see text] Different allyl 2-lithioaryl ethers undergo a tandem carbolithiation/gamma-elimination in Et(2)O/TMEDA affording o-cyclopropyl phenol or naphthol derivatives in a diastereoselective manner. The use of (-)-sparteine as a chiral ligand instead of TMEDA allows the synthesis of cyclopropane derivatives with up 81% ee.
Diazaphospholene‐Catalyzed Radical Reactions from Aryl Halides**
作者:Robert D. Riley、Blake S. N. Huchenski、Karlee L. Bamford、Alexander W. H. Speed
DOI:10.1002/anie.202204088
日期:2022.7.25
Diazaphospholene radical chemistry has been made catalytic with a combination of carbonates and phenylsilane as a terminal reductant. The system is suitable for generation of aryl radicals and intermolecular and intramolecular addition of these radicals.
Electrochemical selenofunctionalization of unactivated alkenes: access to β-hydroxy-selenides
作者:Anil Balajirao Dapkekar、Gedu Satyanarayana
DOI:10.1039/d4ob00105b
日期:——
2-(2-hydroxy-2-methyl-3-(arylselanyl)propoxy)benzoate starting from aryl allyl ethers/allylbenzoates and diaryl diselenides under additive-free electrochemical conditions. This environmentally friendly method was achieved through constant current electrolysis in an undivided cell setup under acid, oxidant, or catalyst-free conditions. Additionally, this technique enabled the synthesis of a variety of β-hydroxy selenides
Palladium-Catalyzed Carbohalogenation: Bromide to Iodide Exchange and Domino Processes
作者:Stephen G. Newman、Jennifer K. Howell、Norman Nicolaus、Mark Lautens
DOI:10.1021/ja206099t
日期:2011.9.28
Aryl bromides have been used to prepare a variety of nitrogen- and oxygen-containing heterocycles featuring new carbon-carbon and carbon-iodine bonds. This palladium-catalyzed carbohalogenation requires potassium iodide for the reaction to proceed in high yields. Additionally, the first examples of domino carbohalogenation reactions have been demonstrated using both aryl iodide and aryl bromide starting materials. Complex products with multiple rings and stereogenic centers are generated in excellent yields with moderate to excellent diastereoselectivities.