Correlation of rates of uncatalyzed and hydroxide-ion catalyzed ketene hydration. A mechanistic application and solvent isotope effects on the uncatalyzed reaction
α,β-Unsaturated ketones were obtained from alkylphenylketene and aroyl chloride via decarbonylation reaction in the presence of catalytic amounts of tetrakis(triphenylphosphine) palladium.
在催化量的四(三苯基膦)钯存在下,通过脱羰反应从烷基苯乙烯酮和芳酰氯获得α,β-不饱和酮。
An asymmetric pericyclic cascade approach to 3-alkyl-3-aryloxindoles: generality, applications and mechanistic investigations
作者:Edward Richmond、Kenneth B. Ling、Nicolas Duguet、Lois B. Manton、Nihan Çelebi-Ölçüm、Yu-Hong Lam、Sezen Alsancak、Alexandra M. Z. Slawin、K. N. Houk、Andrew D. Smith
DOI:10.1039/c4ob02526a
日期:——
The reaction of l-serine derived N-arylnitrones with alkylarylketenes generates 3-alkyl-3-aryloxindoles in good yields and excellent enantioselectivities.
Formal [3+2] Cycloaddition of Ketenes and Oxaziridines Catalyzed by Chiral Lewis Bases: Enantioselective Synthesis of Oxazolin-4-ones
作者:Pan-Lin Shao、Xiang-Yu Chen、Song Ye
DOI:10.1002/anie.201003532
日期:2010.11.2
Choose the right cat.: A highly enantioselectivesynthesis of oxazolin‐4‐ones by the formal [3+2] cycloaddition of ketenes and a racemic oxaziridines has been developed (see scheme; cat.=N‐heterocyclic carbenes for disubstituted ketenes or cinchonaalkaloids for monosubstituted ketenes, Ts=4‐toluenesulfonyl).
Diethyl zinc catalyzed diastereoselective addition of ketenes to (S)-(+)-3-hydroxytetrahydrofuran
作者:Vishnu K. Tandon
DOI:10.1016/s0040-4039(01)01164-9
日期:2001.8
The reaction of (S)-(+)-3-hydroxytetrahydrofuran with phenyl methyl ketene in presence of n-BuLi and Et2Zn results in the formation of the diastereomeric esters (SS+SR) with a high degree of diastereoselectivity (98:2).
NHC-mediated enantioselectiveformal [4+2] cycloadditions of alkylarylketenes with γ-substituted-β,γ-unsaturated α-ketophosphonates is described. A substrate-dependent switch in diastereoselectivity was observed, with γ-aryl α-ketophosphonates providing preferentially the syn-dihydropyranone-phosphonates and γ-methyl α-ketophosphonates favouring the anti-dihydropyranone-phosphonate. In addition, ketene generation