Scope of Palladium-Catalyzed Alkylative Ring Opening
作者:Mark Lautens、Sheldon Hiebert
DOI:10.1021/ja037550s
日期:2004.2.1
We have explored the scope of the palladium-catalyzed nucleophilic ringopening methodology. New highly selective and highly active catalysts have been found for the ringopening of oxabenzonorbornadienes. Employing these catalysts, the addition of various alkyl nucleophiles to oxabenzonorbornadiene has been achieved. In addition, reaction of diethylzinc with [3.2.1] oxabicyclic alkenes has been accomplished
A New and Efficient Hypervalent Iodine−Benzyne Precursor, (Phenyl)[<i>o</i>-(trimethylsilyl)phenyl]iodonium Triflate: Generation, Trapping Reaction, and Nature of Benzyne
the reaction in the presence of furan indicates a quantitative generation of benzyne and its efficient capture by the furan. Similarly, methylbenzynes (22 and 27) are efficiently generated from the corresponding methyl-substituted (trimethylsilyl)phenyliodonium triflates (12 and 13). The preparation of the hypervalent iodine−benzyne precursors, the generation of benzynes, the trapping reactions, and
Remote Electronic Effects in the Rhodium-Catalyzed Nucleophilic Ring Opening of Oxabenzonorbornadienes
作者:Mark Lautens、Gavin A. Schmid、Anh Chau
DOI:10.1021/jo025822o
日期:2002.11.1
We report the application of our rhodium-catalyzednucleophilic ring-opening methodology to unsymmetrically arene-substituted oxabenzonorbornadienes. The regioselectivity of the ringopening was investigated using a variety of nucleophiles that led to a broad selection of dihydronaphthalene products. It was found that good to excellent regioselectivities are obtained using strongly pi-donating substituents
An alternative method for generating arynes from ortho-silylaryl triflates using cesium carbonate and 18-crown-6 is reported. The method was efficiently applied to a variety of reactions between several arynes and arynophiles. We also demonstrated that the efficiency of aryne generation is significantly affected by the alkali metal countercation of the carbonate.
A Selective C−H Deprotonation Strategy to Access Functionalized Arynes by Using Hypervalent Iodine
作者:Sunil K. Sundalam、Aleksandra Nilova、Thomas L. Seidl、David R. Stuart
DOI:10.1002/anie.201603222
日期:2016.7.11
highly functionalized arynesfrom unsymmetrical aryl(mesityl)iodonium tosylate salts. The iodonium salts are prepared in a single pot from either commercially available aryl iodides or arylboronic acids. The aryne intermediates are generated by ortho‐C−H deprotonation of aryl(mesityl)iodonium salt with a commercially available amide base and trapped in a cycloaddition reaction with furan in moderate to good