Metalated Nitriles: Chelation-Controlled Cyclizations to <i>cis</i> and <i>trans</i> Hydrindanes and Decalins
作者:Fraser F. Fleming、Viet Anh Vu、Brian C. Shook、Moshfiqur Rahman、Omar W. Steward
DOI:10.1021/jo062270r
日期:2007.2.1
stereocontrol in alkylations of metalated nitriles. Doubly deprotonating a series of cyclic β-hydroxynitriles triggers cyclizations that implicate metalated nitrile intermediates having configurations imposed by chelation with an adjacent, chiral lithium alkoxide. Identifying chelation as a general stereocontrol element explains several previously anomalous alkylations of metalated nitriles and provides
β-Siloxy Unsaturated Nitriles: Stereoselective Cyclizations to<i> cis-</i> and <i>trans</i>-Decalins
作者:Fraser F. Fleming、Brian C. Shook、Tao Jiang、Omar W. Steward
DOI:10.1021/ol990854s
日期:1999.11.1
precursors to enolate and nitrile anions that cyclize to cis- and trans-decalins, respectively. The stereoelectronic requirements of endocyclic enolates and exocyclic nitrile anions are complementary, providing cis- and trans-decalins from a common intermediate. This cyclization allows the synthesis of diastereomeric cis- and trans-decalins containing a contiguous array of quaternary-tertiary-quaternary
Oxidative DMSO Cyclization Cascade to Bicyclic Hydroxyketonitriles
作者:John Kornfeind、Pravin S. Iyer、Taylor M. Keller、Fraser F. Fleming
DOI:10.1021/acs.joc.2c00364
日期:2022.5.6
Thermolysis of ω-iodoalkyl-β-siloxyalkenenitriles in DMSO triggers an oxidativecyclizationcascade that affords highly oxygenated hydrindanones, decalones, and undecanones. The cyclizationcascade is highly unusual on three counts: the cyclization installs a contiguous array of tertiary–quaternary–tertiary centers, thermolysis equilibrates a quaternary center, and the enolsilyl ether crossed-aldol