Rhodium(II)-Catalyzed Alkyne Amination of Homopropargylic Sulfamate Esters: Stereoselective Synthesis of Functionalized Norcaradienes by Arene Cyclopropanation
作者:Ryan A. Brawn、Kaicheng Zhu、James S. Panek
DOI:10.1021/ol403035g
日期:2014.1.3
followed by arene cyclopropanation to afford unique tetracyclic norcaradiene products bearing a cyclicsulfamate. Products from the arene cyclopropanation (Buchner reaction) can be converted to fused cycloheptatrienes via a ring enlarging electrocyclization after nucleophilic ring opening of the cyclicsulfamate ester.
Preparation and Use of Enantioenriched Allenylsilanes for the Stereoselective Synthesis of Homopropargylic Ethers
作者:Ryan A. Brawn、James S. Panek
DOI:10.1021/ol070936d
日期:2007.7.1
A convenient procedure for the synthesis of highly enantioenriched allenylsilanes by Johnson orthoester Claisen rearrangement of 1-silyl propargylic alcohols is described. Allenylsilanes are then used as carbonnucleophiles in three-component, Lewis acid mediated additions to in situgenerated oxonium ions, resulting in enantioenriched homopropargylic ethers.