Unusual endoperoxide isomerizations: a convenient entry into 2-vinyl-2-cyclopentenones from saturated fulvene endoperoxides
摘要:
An unusual peroxide base-promoted isomerization is uncovered. Saturated endoperoxides derived from fulvenes give rise to 2-vinyl-2-cyclopentenones upon treatment with DBU in CH2CL2 in a one-pot reaction. This methodology is applied to a convenient synthesis of dihydrojasmone. Moreover, functional groups placed on the side chain at C-6 participate in the base-catalyzed isomerizations via conjugate attack at the enone moiety to give 2-cyclopentenones carrying oxygen heterocycles at C-2. (c) 2006 Elsevier Ltd. All rights reserved.
Unusual rearrangement in the reaction of cyclopropanated cyclopentadienes with Et<sub>3</sub>Al/CH<sub>2</sub>I<sub>2</sub> in CH<sub>2</sub>Cl<sub>2</sub>
作者:I. R. Ramazanov、A. V. Yaroslavova、N. R. Yaubasarov、U. M. Dzhemilev
DOI:10.1080/00397911.2018.1511999
日期:2018.10.2
Abstract The reaction of Et3Al/CH2I2 reagent with cyclopropanated spiro[2.4]hepta-4,6-diene and 6-substituted fulvenes in CH2Cl2 was found to lead to the selective formation of rearrangement products through sequential cyclopropyl-allyl rearrangement and cyclopropanation. Graphical Abstrat
Accessing Monosubstituted Cyclopentadienyl Rhodium(I) and Iridium(I) Complexes by a Simultaneous Nucleophilic Addition-Metalation Approach to Fulvenes
作者:Aragorn Laverny、Nicolai Cramer
DOI:10.1021/acs.organomet.0c00550
日期:2020.12.28
Despite advances in the synthesis of polysubstituted cyclopentadienyl metal complexes, the rapid access to a library of monosubstituted Cp bearing metal complexes remains challenging. A convenient and general method to access a broad range of monosubstituted cyclopentadienyl rhodium(I) and iridium(I) complexes is reported. The process involves a direct nucleo-metalation of fulvenes with widely available
Rapid synthesis of fulvenes is achieved using pyrrolidinium/pyrrolidine buffers in anhydrous acetonitrile. Time-dependent UV–vis absorption and NMR spectroscopy reveal that the rate and yield of fulvene formation depend strongly on both the presence of acid in the medium and the choice of solvent, and they are negatively affected by water. Kinetic data have been collected for various substrates, and
An unusual peroxide base-promoted isomerization is uncovered. Saturated endoperoxides derived from fulvenes give rise to 2-vinyl-2-cyclopentenones upon treatment with DBU in CH2CL2 in a one-pot reaction. This methodology is applied to a convenient synthesis of dihydrojasmone. Moreover, functional groups placed on the side chain at C-6 participate in the base-catalyzed isomerizations via conjugate attack at the enone moiety to give 2-cyclopentenones carrying oxygen heterocycles at C-2. (c) 2006 Elsevier Ltd. All rights reserved.