1214919-07-9Relevant academic research and scientific papers
A Diamino Alcohol Catalyzed Enantioselective Crossed Aldol Reaction of Acetaldehyde with Isatins – A Concise Total Synthesis of Antitumor Agents
Subba Reddy, Ummareddy Venkata,Chennapuram, Madhu,Seki, Kento,Seki, Chigusa,Anusha, Bheemreddy,Kwon, Eunsang,Okuyama, Yuko,Uwai, Koji,Tokiwa, Michio,Takeshita, Mitsuhiro,Nakano, Hiroto
, p. 3874 - 3885 (2017)
Enantioselective crossed aldol reactions of isatin derivatives and acetaldehyde have been developed with a series of simple diamino alcohol catalysts to afford 3-substituted 3-hydroxyindolin-2-ones in high chemical yields (up to 95 %) and optical purities (up to 92 % ee). The synthetic potential of the present protocol has been demonstrated by concise, enantioselective, protecting-group-free, and transition metal-free total syntheses of antitumor and antiviral agents with the tryptanthrin architecture, that is, phaitanthrin B and cephalanthrin A, along with the biologically active indolidine alkaloids chimonamidine and donaxaridine as well as the formal synthesis of CPC-1. The highly enantioselective outcome of this catalytic crossed aldol reaction was evaluated by calculating the Gibbs free energies of the possible transition states.
Highly enantioselective aldol reaction of acetaldehyde and isatins only with 4-hydroxydiarylprolinol as catalyst: concise stereoselective synthesis of (R)-convolutamydines B and E, (-)-donaxaridine and (R)-chimonamidine
Chen, Wen-Bing,Du, Xi-Lin,Cun, Lin-Feng,Zhang, Xiao-Mei,Yuan, Wei-Cheng
experimental part, p. 1441 - 1446 (2010/04/04)
A highly enantioselective aldol reaction of acetaldehyde and a wide scope of isatins has been presented only using readily available 4-hydroxydiarylprolinol as catalyst, affording various desired 3-substituted 3-hydroxyindolin-2-one adducts with moderate to high yield (up to 95%) and good enantioselectivities (up to 98% ee). This method not only represents an example of concise stereoselective synthesis of enantiopure (R)-convolutamydines B and E, but also firstly exhibits expedient asymmetric synthesis optically active (-)-donaxaridine and (R)-chimonamidine.
