منابع مشابه
Highly diastereoselective construction of acyclic systems with two adjacent quaternary stereocenters by allylation of ketones.
Unsymmetrical ketones and allyltitanocenes generated by the desulfurizative titanation of γ,γ-disubstituted allyl phenyl sulfides react under highly diastereoselective construction of adjacent quaternary stereocenters (see scheme; R(L) = large group, R(S) = small group). The title reaction is stereospecific: the anti- and syn-homoallylic alcohols are obtained by the reaction of E- and Z-allylic...
متن کاملSynthesis and biological evalution of some thiazolidinone derivatives of acyclic and cyclic ketones as antibacterial agents
Thiosemicarbazone and 4-thiazolidinone derivatives were synthesized in one and two step, respectively from thiosemicarbazide, in satisfactory yields. The structure of the compounds were elucidated by Elemental, IR, and NMR spectral data. The antibacterial activity of these compounds was tested by disc diffusion assay against two Gram-positive and two Gram-negative bacterie. The results showed t...
متن کاملCatalytic asymmetric reductive acyl cross-coupling: synthesis of enantioenriched acyclic α,α-disubstituted ketones.
The first enantioselective Ni-catalyzed reductive acyl cross-coupling has been developed. Treatment of acid chlorides and racemic secondary benzyl chlorides with a Ni(II)/bis(oxazoline) catalyst in the presence of Mn(0) as a stoichiometric reductant generates acyclic α,α-disubstituted ketones in good yields and high enantioselectivity without requiring stoichiometric chiral auxiliaries or prege...
متن کاملSimple highly modular acyclic amine-catalyzed direct enantioselective addition of ketones to nitro-olefins.
Simple, highly modular primary amino acid derivatives catalyze the direct enantioselective addition of ketones to nitro-olefins with high stereocontrol and furnish the corresponding aldol products in high yield with up to >38 1 dr and up to 99% ee.
متن کاملEnantioselective Pd-Catalyzed Decarboxylative Allylic Alkylation of Thiopyranones. Access to Acyclic, Stereogenic α-Quaternary Ketones.
A catalytic, enantioselective decarboxylative allylic alkylation of 4-thiopyranones is reported. The α-quaternary 4-thiopyranones produced are challenging to access by standard enolate alkylation owing to facile ring-opening β-sulfur elimination. In addition, reduction of the carbon-sulfur bonds provides access to elusive acyclic α-quaternary ketones. The alkylated products are obtained in up t...
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ژورنال
عنوان ژورنال: Journal of Chemical Education
سال: 1996
ISSN: 0021-9584,1938-1328
DOI: 10.1021/ed073pa295.2