Enediyne- and Tributyltin Hydride-Mediated Aryl Radical Additions onto Various Radical Acceptors
摘要:
Tandem enediyne-radical cyclizations were carried out on substrates that contain nitrile and ketone radical accepters. The products of these cyclizations and the previously reported tandem enediyne-radical cyclizations containing aldehyde and oxime ether radical accepters were compared with tributyltin hydride-mediated aryl radical addition reactions with 1-bromonaphthalene derivatives containing aldehyde, oxime ether, nitrile, and ketone radical accepters, since these substrates go through similar initial radical intermediates. Although many of the same products were observed using either method of aryl radical generation, there were distinct differences in the product composition and identity depending on which method was used. These differences can probably be primarily attributed to the temperature difference of the two modes of radical generation.
Enediyne- and Tributyltin Hydride-Mediated Aryl Radical Additions onto Various Radical Acceptors
作者:Janet Wisniewski Grissom、Detlef Klingberg、Sabine Meyenburg、Brenda L. Stallman
DOI:10.1021/jo00104a053
日期:1994.12
Tandem enediyne-radical cyclizations were carried out on substrates that contain nitrile and ketone radical accepters. The products of these cyclizations and the previously reported tandem enediyne-radical cyclizations containing aldehyde and oxime ether radical accepters were compared with tributyltin hydride-mediated aryl radical addition reactions with 1-bromonaphthalene derivatives containing aldehyde, oxime ether, nitrile, and ketone radical accepters, since these substrates go through similar initial radical intermediates. Although many of the same products were observed using either method of aryl radical generation, there were distinct differences in the product composition and identity depending on which method was used. These differences can probably be primarily attributed to the temperature difference of the two modes of radical generation.
Platinum- and Ruthenium-Catalyzed Aromatization of Enediynes via Intramolecular Nucleophilic Additions
Catalytic cyclization of enediynes via intramolecular nucleophilic addition was achieved with TpRuPPh3(MeCN)2PF6 and platinum dichloride, giving naphthalene-fused 2,3-dihydrofurans and -pyrroles in good yields. On the basis of experimental results, the mechanism is proposed to involve nucleophilic addition to a Ï-alkyne intermediate, followed by alkyne insertion.