Intermolecular Crossed [2 + 2] Cycloaddition Promoted by Visible-Light Triplet Photosensitization: Expedient Access to Polysubstituted 2-Oxaspiro[3.3]heptanes
作者:Philip R. D. Murray、Willem M. M. Bussink、Geraint H. M. Davies、Farid W. van der Mei、Alyssa H. Antropow、Jacob T. Edwards、Laura Akullian D’Agostino、J. Michael Ellis、Lawrence G. Hamann、Fedor Romanov-Michailidis、Robert R. Knowles
DOI:10.1021/jacs.1c01173
日期:2021.3.17
conditions using a commercially available Ir(III) photosensitizer upon blue light irradiation. This transformation provides access to a range of polysubstituted 2-oxaspiro[3.3]heptane, 2-azaspiro[3.3]heptane, and spiro[3.3]heptanemotifs, which are of prime interest in medicinal chemistry as gem-dimethyl and carbonyl bioisosteres. A variety of further transformations of the initial cycloadducts are demonstrated
higher investment in the development of the corresponding syntheses. This approach requires the development of complex multistep reaction sequences on the solid phase. Employing the proteinphosphatase Cdc25 inhibitor dysidiolide as an example, we demonstrate that this goal can be achieved successfully. The reaction sequences developed led to dysidiolide analogues in overall 8-12 linear steps with
New Wittig reagents, furanmethylids b-e were successfully developed. Their preparation, reactivity, and application toward the natural products synthesis are described in detail. (C) 2003 Elsevier Science Ltd. All rights reserved.
Synthesis of (-)-Untenospongin C, a C21 Furanoterpene Isolated from the Okinawan Sponge Hippospongia Sp.
Starting with (R)-(+)-citronellol (5), the first enantioselective synthesis of (-)-untenospongin C (1), a C-21 furanoterpene isolated from a marine sponge Hippospongia sp., has been achieved, the present synthesis indicating the absolute configuration of 1 as S.
Sulfonamide derivatives of styrylheterocycles as a potent inhibitor of COX-2-mediated prostaglandin E2 production
作者:Chaemin Lim、Minhee Lee、Eun-Jung Park、Ran Cho、Hyen-Joo Park、Seong Jin Lee、Heeyeong Cho、Sang Kook Lee、Sanghee Kim
DOI:10.1016/j.bmcl.2010.09.136
日期:2010.12
The overproduction of prostaglandin E-2 (PGE(2)) plays an important role in a variety of pathophysiological processes including inflammation and carcinogenesis. Therefore, the modulation of PGE(2) production is a promising target in the design of chemotherapeutic agents. In the present study, the inhibitory effects of a series of styrylheterocycles having either a p-SO2NH2 or p-SO2Me group on the production of cyclooxygenase-2-mediated PGE(2) were evaluated in lipopolysaccharide-stimulated RAW264.7 murine macrophages. Among the series of styrylheterocycle derivatives, (E)-4-(2-(thiophen-3-yl)vinyl) benzenesulfonamide exhibited a potent inhibitory activity, with an IC50 value of 0.013 mu M. The inhibitory activity against the overproduction of PGE(2) by the active compound was found to be due in part to the suppression of COX-2 mRNA expression. (C) 2010 Elsevier Ltd. All rights reserved.