Rh(I)-Catalyzed Cyclocarbonylation of Allenol Esters To Prepare Acetoxy 4-Alkylidenecyclopent-3-en-2-ones
作者:Kay M. Brummond、Matthew M. Davis、Chaofeng Huang
DOI:10.1021/jo901459t
日期:2009.11.6
A Rh(I)-catalyzed cyclocarbonylation reaction of allenol esters has been examined and its synthetic viability established for the conversion of trisubstituted allenes to bicyclo[4.3.0] and -[5.3.0] skeletons possessing an α-acetoxy cyclopentadienone. Tetrasubstituted allenol acetates gave elimination products, providing examples of a cyclocarbonylation reaction between an alkyne and a latent cumulene
Tandem Functionalization of Nonactivated Alkenes and Alkynes in Intramolecular <i>N</i>-Acyloxyiminium Ion Carbocyclization. Synthesis of 6-Substituted Hydroindole 2-Carboxylic Acids
作者:Stephen Hanessian、Martin Tremblay
DOI:10.1021/ol040053b
日期:2004.12.1
[reaction: see text] Five-membered N-Boc acyliminium ions derived from L-pyroglutamic acid harboring 4-butenyl and 4-butynyl tethers undergo Lewis acid-mediated halo and tandem Friedel-Crafts carbocyclization within minutes at -78 degrees C to give stereodefined 6-substituted octahydroindole and hexahydroindole 2-carboxylic acid methyl esters, respectively. The cyclic vinyl bromides are excellent substrates
Rhodium(I)-Catalyzed Cycloisomerization
Reaction of Yne-Allenamides: An Approach to Cyclic Enamides
作者:Kay Brummond、Bingli Yan
DOI:10.1055/s-2008-1078169
日期:——
In this paper, we demonstrate a successful conversion of alkynyl allenamides to triene-containing heterocycles via a rhodium(I)-catalyzed cycloisomerization reaction.
在本文中,我们展示了通过铑(I)催化的环异构化反应将炔基烯酰胺成功转化为含三烯杂环的过程。
The generation and cyclisation of pyridinium radicals as a potential route to indolizidine alkaloids
作者:Adrian P. Dobbs、Keith Jones、Ken T. Veal
DOI:10.1016/s0040-4039(97)01178-7
日期:1997.7
The cyclisation of pyridine radicals derived from 2-bromo-N-alkyl pyridinium salts is described. The subsequent hydrogenation of the pyridinium salts is shown to give both the indolizidine and quinolizidine skeletons.
A new route to BCD tricyclic fragment of C19-diterpenoid alkaloids via intramolecular Pauson-Khand reaction followed by anionic 1,2-migration rearrangement
assembly of the bridged tricyclic BCD ring system of C19-diterpenoid alkaloids bearing a characteristic hydroxy group on ring C has been developed. The synthesis features an efficient intramolecular Pauson-Khand reaction and an exclusive anionic 1,2-migration rearrangement to generate the unique bicyclo[3.2.1]octane moiety of the CD-ring on the seven-membered B-ring.