Solvent-Free Enantioselective Organocatalyzed Aldol Reactions
نویسندگان
چکیده
منابع مشابه
Prolinethioamides versus Prolinamides in Organocatalyzed Aldol Reactions - A Comparative Study
Various organocatalysts have been developed for the aldol reaction but particular attention has been paid to prolinamide derivatives. They are easy to prepare and their catalytic activity can be readily tuned through structural modification. In this review, the comparison of catalytic activities between prolinethioamides and their respective amides in direct asymmetric aldol reactions is presen...
متن کاملEnantioselective direct aldol reactions catalyzed by L-prolinamide derivatives.
l-Prolinamides 2, prepared from l-proline and simple aliphatic and aromatic amines, have been found to be active catalysts for the direct aldol reaction of 4-nitrobenzaldehyde with neat acetone at room temperature. They give moderate enantioselectivities of up to 46% enantiomeric excess (ee). The enantioselectivity increases as the amide N-H becomes a better hydrogen bond donor. l-Prolinamides ...
متن کاملEnantioselective total synthesis of (-)-pironetin: iterative aldol reactions of thiazolidinethiones.
The enantioselective total synthesis of pironetin has been achieved in 11 steps from known aldehyde 2. The synthesis relies on the formation of 5 out of 6 stereocenters through titanium mediated iterative aldol reactions. Key steps in this synthesis include an acetal aldol reaction to establish the stereochemistry at C8 and C9, an acetate aldol reaction, and "Evans" syn aldol reaction.
متن کاملVery high stereoselectivity in organocatalyzed desymmetrizing aldol reactions of 3-substituted cyclobutanones.
N-Phenylsulfonyl (S)-proline catalyzes the direct aldol reaction of 3-substituted cyclobutanones and aryl aldehydes in good yield and with excellent diastereoselectivity and enantioselectivity. This desymmetrization process provides highly functionalized cyclobutanones with control over three contiguous stereogenic centers.
متن کاملEnantioselective organocatalyzed Henry reaction with fluoromethyl ketones.
Remarkable generality in scope of new C9-benzoylcupreines bearing electron-withdrawing substituents for the nitroaldol condensation with fluoromethyl ketones is presented. Both tri- and difluoromethyl ketones provided excellent levels of stereoinduction (ee 76-99%) under mild reaction conditions and low loading of catalyst (1-5 mol%).
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Mini-Reviews in Organic Chemistry
سال: 2014
ISSN: 1570-193X
DOI: 10.2174/1570193x1102140609115452