Effect of carbenoid structure on the reactivity of rhodium-stabilized carbenoids
作者:Huw M.L. Davies、L. Mark Hodges、Julius J. Matasi、Tore Hansen、Douglas G. Stafford
DOI:10.1016/s0040-4039(98)00836-3
日期:1998.6
outcome of rhodium(II) pivalate catalyzed decomposition of diaozoacetates in the presence of cyclohexane is highly dependent on carbenoidstructure. Carbenoids derived from phenyldiazoacetates or diazoketoesters undergo high yielding intermolecular CH insertions while other carbenoid systems undergo rearrangements, dimerization or trimerization.
Reaction of 2H-1-benzothiete with diazo compounds in the presence of rhodium(II) acetate
作者:Herbert Meier、Dieter Gröschl
DOI:10.1016/0040-4039(95)01239-e
日期:1995.8
2,3-Dihydrobenzo[b]thiophenes (7a-e) were prepared by the Rh2+ catalyzed reaction of 2H-1-benzothiete (1) and diazocompounds (3a-e). α,β-Unsaturated diazo esters (3b,e) and diazoketones (3d,e) yielded additionally 4,5-dihydro-1-benzothiepins (11b,c) and 5H-4,1-benzoxathiepins (12d,e), respectively.
通过2 H -1-苯并噻吨(1)与重氮化合物(3a-e)的Rh 2+催化反应,制备了2,3-二氢苯并[b]噻吩(7a -e)。α,β-不饱和重氮酯(3b,e)和重氮酮(3d,e)额外产生4,5-二氢-1-苯并噻吩(11b,c)和5 H -4,1-苯并噻吩(12d,e) , 分别。
Divergent reaction pathways between rhodium(II)-stabilized vinylcarbenoids and benzenes
作者:Huw M. L. Davies、H. David Smith、Baihua Hu、Scott M. Klenzak、Frederick J. Hegner
DOI:10.1021/jo00051a041
日期:1992.12
Rhodium(II) carboxylate stabilized vinylcarbenoids reacted intermolecularly with benzenoid compounds by two distinct modes. With benzene, alkylbenzenes, and 1-methoxynaphthalene, 3 + 4 annulations were observed, presumably arising through initial cyclopropanation followed by a Cope rearrangement. In contrast, alkylation products were formed with methoxy-substituted benzenes. In an intramolecular reaction a delicate balance existed between norcaradiene formation, 3 + 4 annulation, and 3 + 2 annulation.
Versatile synthesis of tropones by reaction of rhodium(II)-stabilized vinylcarbenoids with 1-methoxy-1-[(trimethylsilyl)oxy]buta-1,3-diene
作者:Huw M. L. Davies、T. Jeffrey Clark、Garland F. Kimmer
DOI:10.1021/jo00022a041
日期:1991.10
Rhodium(II)-catalyzed decomposition of vinyldiazomethanes in the presence of 1-methoxy-1-[(trimethylsilyl)oxy]buta-1,3-diene leads to [3 + 4] annulation products by a tandem cyclopropanation/Cope rearrangement sequence. The resulting cycloheptadienes are readily converted to cycloheptatrienones either by hydrolysis with mild acid followed by oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone or by treatment with dichloroethoxyoxovanadium. The efficiency of the general strategy was demonstrated through a short synthesis of nezukone.