Design and Development of Highly Effective Lewis Acid Catalysts for Enantioselective Diels−Alder Reactions
作者:Yong Huang、Tetsuo Iwama、Viresh H. Rawal
DOI:10.1021/ja026088t
日期:2002.5.1
report describes the design and development of chiral Co(III)-salen catalysts for enantioselectiveDiels-Alderreactions. A crystal structure of a Co-salen catalyst with two equivalents of benzaldehyde provided insight on the factors that may be important for enantioselectivity. On the basis of this structural information, new catalysts were prepared in which the "bay region" tert-butyl groups were replaced
Sodium Salts of Anionic Chiral Cobalt(III) Complexes as Catalysts of the Enantioselective Povarov Reaction
作者:Jie Yu、Hua-Jie Jiang、Ya Zhou、Shi-Wei Luo、Liu-Zhu Gong
DOI:10.1002/anie.201504790
日期:2015.9.14
The sodium salts of anionic chiral cobalt(III) complexes (CCC−Na+) have been found to be efficient catalysts of the asymmetric Povarov reaction of easily accessible dienophiles, such as 2,3‐dihydrofuran, ethyl vinyl ether, and an N‐protected 2,3‐dihydropyrrole, with 2‐azadienes. Ring‐fused tetrahydroquinolines with up to three contiguous stereogenic centers were thus obtained in high yields, excellent
Bimetallic Schiff-base complexes with different bridging parts and silyl-substituents were applied for stereoselective ROP ofrac-LA, and copolymerisation ofrac-LA/ε-CL.
Expedient, High-Yielding Synthesis of Silyl-Substituted Salen Ligands
作者:Avinash N. Thadani、Yong Huang、Viresh H. Rawal
DOI:10.1021/ol0713436
日期:2007.9.1
enantioselective catalysts. The salicylaldehyde precursors are synthesized from the silyl ethers of 2,6-dibromophenols via a one-pot double lithium halogen exchanges, to induce an intramolecular retro-Brook rearrangement and allow introduction of the aldehyde group. Condensation of the salicylaldehyde products with a chiral diamine affords the silyl-substituted salen ligands in high yields. The use of other