A Rhodium(I)-Catalyzed Formal Allenic Alder Ene Reaction for the Rapid and Stereoselective Assembly of Cross-Conjugated Trienes
作者:Kay M. Brummond、Hongfeng Chen、Peter Sill、Lingfeng You
DOI:10.1021/ja027588p
日期:2002.12.1
A rhodium(I)-catalyzed allenic Alderenereaction to prepare cross-conjugated trienes has been discovered. The scope and limitations are currently being investigated, and the results obtained to date are reported on. This method shows enticing functional group compatibility by tolerating terminal and internal alkynes, hydroxyl, sulfonamide, ether, and diester groups. Progress has been made to increase
Asymmetricalkylation of 2,3-alkadienyl phosphates with soft carbon nucleophiles proceeds efficiently in the presence of palladium complex catalyst bearing MeOBIPHEP or BINAP ligand to give opticallyactive functionalized allenes up to 90% ee.
在带有 MeOBIPHEP 或 BINAP 配体的钯配合物催化剂存在下,2,3-链二烯基磷酸酯与软碳亲核试剂的不对称烷基化可有效进行,得到高达 90% ee 的旋光功能化丙二烯。
The intramolecular cobalt-mediated reaction of α,ω-allenynes 8 leads to bicyclic dienones 10 and α-alkylidenecyclopentenones 11; regioselectivity depends on the substitution pattern of the allenic moiety.
γ-Allenic α-amino acids can be obtained by a three-step sequence from the phosphates of α-allenic alcohols: i) palladium-catalyzed alkylation of a Schiff base derived from glycine ester by these phosphates, ii) acidic hydrolysis of the imine functionality, and iii) saponification of the resulting amino esters.
[GRAPHICS]Asymmetric amination of 2,3-allenyl phosphates with nitrogen nucleophiles such as amines, hydroxylamines, and imides can be performed efficiently using a combination of zerovalent palladium complexes and SEGPHOS or MeOBlPHEP ligand, affording the corresponding optically active 1-aminated derivatives with enantiomeric excess of up to 97% ee.