Palladium(0) catalyzed regioselective carbonyl propargylation across tetragonal tin(ii) oxide via redox transmetallationElectronic supplementary information (ESI) available: general method and experimental procedure and spectroscopic data for compounds 3–10. See http://www.rsc.org/suppdata/cc/b2/b211555g/
作者:Moloy Banerjee、Sujit Roy
DOI:10.1039/b211555g
日期:2003.2.7
Facile homopropargylation of aldehydes by propargyl bromides over tetragonal tin(II)oxide and catalytic palladium(0) occurs which is proposed to involve the prior formation of dinuclear allenylpalladium followed by redox transmetallation to β-SnO.
Tandem Brønsted Acid Promoted and Nazarov Carbocyclizations of Enyne Acetals to Hydroazulenones
作者:Luz Escalante、Carlos González-Rodríguez、Jesús A. Varela、Carlos Saá
DOI:10.1002/anie.201205823
日期:2012.12.3
Ring the changes: Enyne acetals were easily converted into hydroazulene skeletons by a new and efficient metal‐free route involving a Brønsted acid promoted carbocyclization and a subsequent stereospecific Nazarov cyclization (see scheme). The versatility of this transformation also allowed assembly of interesting heteroaromatic tricyclic systems.
Rearrangements of bridged diallenes. A facile synthesis of novel condensed heterocycles by tandem [3,3]-sigmatropic rearrangement and double intramolecular michael addition of diallenyl disulfides and diselenides. Isolation of stable diallenyl diselenides
作者:Samuel Braverman、Meir Freund
DOI:10.1016/s0040-4020(01)87773-5
日期:1990.1
undergo consecutive 3,3]-sigmatropic rearrangement and double Michael addition, to the observed products. This mechanism is supported by the isolation of bis-τ,τ- diisopropylallenyl and bis-τ-methyl-τ-isopropylallenyl diselenides, under the same reaction conditions, and the rearrangement of the latter to the expected selenoloseleophene 33. The synthesis of the novel mixed selenolothiophene 35 by treatment
Natural acetylenes. Part XL. Syntheses of polyacetylenic C18 and C16 esters with 9-ene-12,14-diyne unsaturation, and their labelling
作者:Alexander G. Fallis、Milton T. W. Hearn、Ewart R. H. Jones、Viktor Thaller、John L. Turner
DOI:10.1039/p19730000743
日期:——
The esters R[CC]2·CH2CH[graphics omitted]CH·[CH2]7·CO2MeR = Me[CH2]2, MeCC, cis- or trans-MeCHCH, trans-HO·CH2·CHCH, HO·CH2·CC, cis- or trans-MeO2C·CHCH, MeO2C·CC, (EtO)2CH, OHC, or, H2N·OC} were prepared from the Wittig salt Me3Si·CC·CH2·CH2·PPh3I–via ICC·CH2·CH[graphics omitted]CH·[CH2]7·CO2Me; several were specifically labelled [at C(9), C(17), and C(18)]. The Wittig salt offers a general route
An Improved Synthesis of Natural Product Inspired Chromenopyrrolizines and Chromenoindolizines Scaffolds: Rapid Access to the Diverse Pyrrolizine Analogs of Aza-Medicarpin and Tetracyclic Isolamellarin Core through a General Base and Metal Free Strategy
作者:Tabrez Khan、Virendra Kumar、Oindreela Das
DOI:10.1246/bcsj.20160205
日期:2016.11.15
improved synthesis for easy access to the natural product inspired chromenopyrrolizine and chromenoindolizine scaffolds is delineated. The strategy involves controlled thermal activation of diverse salicylaldehyde tethered dipolarophiles having the strategically stationed activating substituents with proline/pipecolic acid for the facile [3+2] cycloaddition of the in situ generated azomethine ylides and