作者:Vera J. Meyer、Liang Fu、Fabian Marquardt、Meike Niggemann
DOI:10.1002/adsc.201300253
日期:2013.7.8
A cycloisomerization of enynes with a benign calcium catalyst is presented exploring a complementary reactivity to that usually found in transition and noble metal‐catalyzed reactions. Thereby, a systematic investigation of the π‐activation of alkynes with reactive carbocations has been realized and ketones of various ring sizes were easily accessed. We are certain that these basic investigations will
Asymmetric Au-catalyzed domino cyclization/nucleophile addition reactions of enynes in the presence of water, methanol and electron-rich aromatic derivatives
作者:Alexandre Pradal、Chung-Meng Chao、Maxime R. Vitale、Patrick Y. Toullec、Véronique Michelet
DOI:10.1016/j.tet.2011.03.071
日期:2011.6
system is described for the asymmetric domino cyclization/functionalization reactions of functionalized 1,6-enynes in the presence of an external nucleophile. The use of (R)-4-MeO-3,5-(t-Bu)2-MeOBIHEP ligand associated with gold led to clean rearrangements implying the formal addition of an oxygen or carbon nucleophile to an alkene followed by a cyclization process. The enantiomeric excesses were highly
作者:Allegra Franchino、Àlex Martí、Antonio M. Echavarren
DOI:10.1021/jacs.1c11978
日期:2022.3.2
data, and studies of solvent and nonlineareffects substantiate the key H-bonding interaction at the heart of the catalytic system. This conceptually novel approach, which lies at the intersection of metal catalysis, H-bond organocatalysis, and asymmetric counterion-directed catalysis, provides a blueprint for the development of supramolecularly assembled chiral ligands for metal complexes.
Gold(I) complexes are the most active catalysts for alkoxy- or hydroxycyclization and for skeletalrearrangement reactions of 1,6-enynes. Intramolecular alkoxycyclizations also proceed efficiently in the presence of gold(I) catalysts. The first examples of the skeletalrearrangement of enynes by the endocyclic cyclization pathway are also documented. Iron(III) is also able to catalyze exo and endo
Cyclizations of Enynes Catalyzed by PtCl<sub>2</sub> or Other Transition Metal Chlorides: Divergent Reaction Pathways
作者:María Méndez、M. Paz Muñoz、Cristina Nevado、Diego J. Cárdenas、Antonio M. Echavarren
DOI:10.1021/ja0112184
日期:2001.10.31
(eta2-alkyne)platinum complex. The formation of the C-C and C-O bonds takes place stereoselectively by trans addition of the electrophile derived from the alkyne and the nucleophile to the double bond of the enyne. Formation of five- or six-membered carbo- or heterocycles could be obtained from 1-en-6-ynes depending on the substituents on the alkene or at the tether. Although more limited in scope, Ru(II) and Au(III)