Diastereoselective Friedel–Crafts Alkylation of Hydronaphthalenes
摘要:
An efficient and versatile synthesis of chiral tetralins has been developed using both inter- and intra-molecular Friedel Crafts alkylation as a key step. The readily available hydronaphthalene substrates were prepared via a highly enantioselective metal-catalyzed ring opening of meso-oxabicyclic alkenes followed by hydrogenation. A wide variety of complex tetracyclic compounds have been isolated with high levels of regio-, diastereo-, and enantioselectivity.
Fesulphos-Palladium(II) Complexes as Well-Defined Catalysts for Enantioselective Ring Opening of Meso Heterobicyclic Alkenes with Organozinc Reagents
作者:Silvia Cabrera、Ramón Gómez Arrayás、Inés Alonso、Juan C. Carretero
DOI:10.1021/ja055692b
日期:2005.12.1
The air-stable and readily available cationic methyl palladium(II) complexes of planarchiral Fesulphos ligands [(Fesulphos)Pd(Me)(PhCN)]+ X- are highlyefficientcatalysts for the alkylative ringopening of oxa- and azabicyclicalkenes with dialkylzinc reagents, showing broad scope with regards to both the bicyclic substrate and the dialkylzinc reagent. Catalyst loading as low as 0.5 mol % is sufficient
Nickel-catalyzed <i>syn</i>-stereocontrolled ring-opening of oxa- and azabicyclic alkenes with dialkylzinc reagents
作者:Yingying Deng、Wen Yang、Yongqi Yao、Xin Yang、Xiongjun Zuo、Dingqiao Yang
DOI:10.1039/c8ob02864h
日期:——
A new nickel-catalyzed syn-stereocontrolled ring-opening of oxa- and azabicyclicalkenes with dialkylzinc reagents was developed, which afforded the corresponding cis-2-alkyl-1,2-dihydronaphthalen-1-ols and 1,2-alkyl amide derivatives in moderate to excellent yields (up to 99% yield) under mild conditions. In this work, we successfully avoided obtaining hydride addition byproducts arising from β-hydride
Mechanistic Studies of the Palladium-Catalyzed Ring Opening of Oxabicyclic Alkenes with Dialkylzinc
作者:Mark Lautens、Sheldon Hiebert、Jean-Luc Renaud
DOI:10.1021/ja010498k
日期:2001.7.1
The mechanism of the palladium-catalyzed ring opening of oxabicyclicalkenes with dialkylzinc has been studied. Experiments which rule out a π-allyl mechanism were carried out. Trapping carbometalated products and synthesis and successful reaction of alkyl palladium species provided strong evidence in favor of an enantioselective carbopalladation as the key step in the mechanism. The studies also suggest
Copper-Catalyzed Ring-Opening of Heterobicyclic Alkenes with Grignard Reagents: Remarkably High<i>anti</i>-Stereocontrol
作者:Ramón Gómez Arrayás、Juan Carlos Carretero、Silvia Cabrera
DOI:10.1055/s-2006-926379
日期:——
protocols for the ring-opening reaction of heterobicyclic alkenes with carbon nucleophiles which typically occur with syn selectivity, the alkylative ring-opening reaction of [2.2.1]oxa- and azabicyclicalkenes with Grignard reagents in the presence of a catalytic amount of copper(I) takes place with very high or complete anti-stereocontrol under smooth reaction conditions. This new procedure proved to
1-Phosphino-2-sulfenylferrocenes: efficient ligands in enantioselective palladium-catalyzed allylic substitutions and ring opening of 7-oxabenzonorbornadienes
作者:Julián Priego、Olga García Mancheño、Silvia Cabrera、Ramón Gómez Arrayás、Tomás Llamas、Juan C. Carretero
DOI:10.1039/b207344g
日期:——
The readily available 1-phosphino-2-sulfenylferrocenes 1 provide very high enantioselectivities in Pd-catalyzed allylic substitution reactions and alkylativeringopening of 7-oxabenzonorbornadiene with dialkylzinc reagents.