Flexible Stereoselective Functionalizations of Ketones through Umpolung with Hypervalent Iodine Reagents
作者:Pushpak Mizar、Thomas Wirth
DOI:10.1002/anie.201400405
日期:2014.6.2
The functionalization of carbonyl compounds in the α‐position has gathered much attention as a synthetic route because of the wide biological importance of such products. Through polarity reversal, or “umpolung”, we show here that typical nucleophiles, such as oxygen, nitrogen, and even carbon nucleophiles, can be used for addition reactions after tethering them to enol ethers. Our findings allow novel
Asymmetric oxidation of enol phosphates to α-hydroxy ketones by (salen)manganese(III) complex. Effects of the substitution pattern of enol phosphates on the stereochemistry of oxygen transfer
作者:Marek Koprowski、Jerzy Łuczak、Ewa Krawczyk
DOI:10.1016/j.tet.2006.09.100
日期:2006.12
j and Z-configured enol phosphates containing aryloxy substituents in the phosphate group 2b, d, and h afforded optically active α-hydroxy ketones 4a–j of opposite configuration with good to high enantioselectivity. The influence of electronic and steric effects of the enol phosphate substituents on the stereoselectivity of oxidation was studied.
were synthesized with high enantiopurity by asymmetric decarboxylative chlorination and subsequent nucleophilicsubstitution. We recently reported the asymmetric decarboxylative chlorination of β-ketocarboxylic acids in the presence of a chiral primary amine catalyst to obtain α-chloroketones with high enantiopurity. Here, we found that nucleophilicsubstitution of the resulting α-chloroketones with tetrabutylammonium
New methods and reagents in organic synthesis. 75. asymmetric synthesis of α-hydroxy ketones using chiral phase transfer catalysts
作者:Moriyasu Masui、Akira Ando、Takayuki Shioiri
DOI:10.1016/0040-4039(88)85224-9
日期:——
Optically active α-hydroxyketones are obtained by oxidation of achiral ketones with molecular oxygen in two phase system usingchiralphasetransfercatalysts.
光学活性α-羟基酮是通过使用手性相转移催化剂在两相体系中用分子氧将非手性酮氧化而获得的。
Diastereoselective Ring Expansion Rearrangements of (Benzocyclobutenone)-and (Benzocyclobutenedione)chromium Complexes: Syntheses of Substituted 1-Indanone and 1,3-Indandione Complexes
the exo face of the organic ligand. If acyl anion equivalents are used as nucleophiles, deprotection of the carbonyl functions of the adducts causes ringexpansion reactions to occur. Among these a rare example of an anion-accelerated 1-vinylcyclobutenol–cyclohexadienol rearrangement is reported which results, after isomerization, in a naphthol complex. Other ringexpansion reactions gave coordinated