Cyclization of Dicobalthexacarbonyl Complexes of Allyl Propargyl Ethers on the Surface of Chromatography Adsorbents. A Convenient Method for the Preparation of Substituted 3-Oxabicyclo[3.3.0]oct-5-en-7-one and 4-Hydroxymethyl-2-cyclopenten-1-one Derivatives from Common Precursors
作者:W. A. Smit、S. O. Simonyan、V. A. Tarasov、G. S. Mikaelian、A. S. Gybin、I. I. Ibragimov、R. Caple、D. Froen、A. Kreager
DOI:10.1055/s-1989-27296
日期:——
Allyl propargyl ethers serve as valuable precursors for short and efficient syntheses of the title compounds via an intramolecular [2 + 2 + 1] Khand-Pauson cyclization under the novel procedure of adsorption-promoted (dry state) conditions.
Ring Expansions Within the Gold-Catalyzed Cycloisomerization of<i>O</i>-Tethered 1,6-Enynes. Application to the Synthesis of Natural-Product-like Macrocycles
Goldenyne: O‐tethered 1,6‐enynes that contain a strained ring at the 3 position can cycloisomerize upon cationic gold(I) catalysis through a ring‐expansion process. A two‐step sequence allows the transformation of the cyclized compounds into ketomacrolactones, which are reminiscent of natural products.
Intramolecular cyclization of dicobalt hexacarbonyl complexes of allyl propyl ethers on adsorbent surfaces. A convenient mode of preparation of 3-oxabicyclo[3.3.0]octenes and 4-hydroxymethylcyclopentenone derivatives
作者:V. A. Smit、S. O. Simonyan、V. A. Tarasov、A. S. Gybin、G. S. Mika�lyan、A. S. Shashkov、S. S. Mamyan、I. I. Ibragimov、R. K�ipl
DOI:10.1007/bf00952633
日期:1988.12
Ethylene-Promoted versus Ethylene-Free Enyne Metathesis
作者:Anne G. D. Grotevendt、Justin A. M. Lummiss、Melanie L. Mastronardi、Deryn E. Fogg
DOI:10.1021/ja207388v
日期:2011.10.12
The role of ethylene in promoting metathesis of acetylenic enynes is probed within the context of ring-closing enyne metathesis, using first- and second-generation Grubbs catalysts. Under inert atmosphere, rapid catalyst deactivation is observed by calibrated GC-FID analysis for substrates with minimal propargylic bulk. MALDI-TOF mass spectra reveal a Ru(enyne)(2) derivative that exhibits very low reactivity toward both enyne and ethylene. Under ethylene, formation of this species is suppressed. Enynes with bulky propargylic groups are not susceptible to this catalyst deactivation pathway, even under N-2 atmosphere.
PtCl<sub>2</sub>-Catalyzed Tandem Triple Migration Reaction toward (<i>Z</i>)-1,5-Dien-2-yl Esters
A novel method for the selective synthesis of (Z)-1,5-dien-2-yl esters has been developed though Pt(II)-catalyzed tandem 1,2-acyl and 1,2-hydride migration, along with an allyl migration reaction of propargylic carboxylates with electronically unbiased internal alkynes. The unusual selectivity of 1,2-acyloxy migration was realized.