A Novel One-Pot, Three-Component Synthesis of 5-Imino-2,3,5,8-tetrahydropyrazolo[1,2-a]pyridazin-1-one Derivatives
作者:Yong-Min Liang、Bo Qian、Ming-Jin Fan、Yong-Xin Xie、Lu-Yong Wu、Yun Shi
DOI:10.1055/s-0028-1088070
日期:2009.5
It was found that the zwitterionic intermediate obtained from the addition of isocyanides to dimethyl acetylenedicarboxylate could react with 1,3-dipolar compounds under mild conditions to produce 5-imino-2,3,5,8-tetrahydropyrazolo[1,2-a]pyridazin-1-one derivatives in high yields. A plausible mechanism was also discussed for this process.
Metal Amides as the Simplest Acid/Base Catalysts for Stereoselective Carbon-Carbon Bond-Forming Reactions
作者:Yasuhiro Yamashita、Shū Kobayashi
DOI:10.1002/chem.201300908
日期:2013.7.15
paper, new possibilities for metalamides are described. Although typical metalamides are recognized as strong stoichiometric bases for deprotonation of inert or less acidic hydrogen atoms, transition‐metalamides, namely silver and copper amides, show interesting abilities as one of the simplestacid/basecatalysts in stereoselectivecarbon–carbon bond‐forming reactions.
An enantioselective formal total synthesis of (+)-manzacidin C is described. A key feature of the synthesis is the construction of two chiral centers via the asymmetric 1,3-dipolar cycloaddition of an azomethine imine to methallyl alcohol by the use of (S,S)-DIPT as a chiral auxiliary.
Rhodium-Catalyzed Asymmetric Arylation of Azomethine Imines
作者:Ryo Shintani、Ying-Teck Soh、Tamio Hayashi
DOI:10.1021/ol101700v
日期:2010.9.17
A rhodium-catalyzed addition of sodium tetraarylborates to azomethine imines has been described. Highly efficient asymmetric catalysis has also been achieved by employing a chiral diene ligand to give 1-(diarylmethyl)pyrazolidin-3-ones with high enantioselectivity.
An efficient asymmetric [2 + 3] annulation of simplealdehydes with N,N′-cyclic azomethine imines via oxidative N-heterocyclic carbene (NHC) catalysis is disclosed, affording bicyclic pyrazolidinones bearing two vicinal tertiary stereogenic centers with moderate to good yields (56–84% for 19 examples), good to excellent diastereoselectivities (>20:1 for 17 examples), and good to excellent enantioselectivities