A One-Pot Palladium-Catalyzed Allylic Alkylation and Wittig Reaction of Phosphorus Ylides
作者:Wen-Bo Liu、Hu He、Li-Xin Dai、Shu-Li You
DOI:10.1002/chem.201000316
日期:2010.7.5
Put a(n) (y)lid(e) on it! The one‐pot palladium‐catalyzed allylic alkylation and Wittigreaction of phosphorus ylides with various aldehydes and ketenes has been realized, which produce skipped dienes, including trisubstituted alkenes and tetrasubstituted allenes, respectively (see scheme), in moderate to good overall yields.
Ir-Catalyzed Regio- and Enantioselective Friedel–Crafts-Type Allylic Alkylation of Indoles
作者:Wen-Bo Liu、Hu He、Li-Xin Dai、Shu-Li You
DOI:10.1021/ol800409d
日期:2008.5.1
Highly regio- and enantioselective Ir-catalyzed Friedel-Crafts type allylic alkylation of indoles have been realized using [Ir(COD)Cl]2/phosphoramidite ligand 1a, affording the branched products with up to >97/3 branched-linear ratio and 92% ee.
Enantioselective Ir-catalyzed allylic aminations with hydroxamic acid derivatives are described. Catalysts were prepared in situ from [Ir(cod)Cl](2) or [Ir(dbcot)Cl](2), a phosphoramidite and base. In addition, pure (pi-allyl)Ir complexes containing cod or dbcot as auxiliary ligands were used. Very high degrees of regio- and enantioselectivity were achieved. The reaction products were transformed Into piperidine derivatives suited as precursors for aza-sugars.
Addition of Organometallic Reagents to Chiral<i>N</i>‐Methoxylactams: Enantioselective Syntheses of Pyrrolidines and Piperidines
Enantioselective iridium‐catalyzed allylic substitutions were used to prepare N‐allyl hydroxamic acid derivatives that were suitable for ring‐closing metathesis, giving N‐methoxylactams. Reactions of these derivatives with Grignard or organolithium compounds gave hemiaminals, which could be reduced diastereoselectively via acyliminium intermediates to give cis‐piperidines or cis‐pyrrolidines with substituents