A highly enantio‐ and regioselective hydrosulfonylation of 1,3‐dienes with sulfonyl hydrazides has been realized by using a palladium catalyst containing a monodentate chiral spiro phosphoramidite ligand. The reaction provided an efficient approach to synthetically useful chiral allylic sulfones. Mechanistic studies suggest that the reaction proceeds through the formation of an allyl hydrazine intermediate
TRANSFER OF ASYMMETRY BY THE PALLADIUM-CATALYZED ALKYLATION OF CHIRAL ALLYLIC SULFINATES
作者:Kunio Hiroi、Ryuichi Kitayama、Shuko Sato
DOI:10.1246/cl.1984.929
日期:1984.6.5
The palladium-catalyzed substitution of chiral allylic sulfinates was performed by the initial transformation of the sulfinates into allyl sulfones and the subsequent alkylation of the sulfones with retention of configuration. Reaction of trans- and cis-2-butenyl (S)-(−)-p-toluenesulfinate with the sodium salt of dimethyl malonate was undertaken in the presence of tetrakis(triphenylphosphine)palladium and triphenylphosphine to produce dimethyl (S)-(+)- and (R)-(−)-1-buten-3-ylmalonate, respectively, with the α-alkylated product, dimethyl 2-butenylmalonate.
Dramatic solvent effects and stereospecificity in allylic sulphinate–sulphone rearrangements
作者:Kunio Hiroi、Ryuichi Kitayama、Shuko Sato
DOI:10.1039/c39830001470
日期:——
Dramaticsolventeffects were observed in the thermolysis of allyl sulphinates; heating of chiral trans- and cis-allyl sulphinates (S)-(–)-(1a–g) in N,N-dimethylformamide at 90–120 °C provided chiral sulphones (2a–d) in good yields with very high stereospecificity.
Palladium-catalysed allylic sulphinate–sulphone rearrangements; asymmetric induction in the palladium-catalysed transfer of chiral sulphinates to sulphones
作者:Kunio Hiroi、Ryuichi Kitayama、Shuko Sato
DOI:10.1039/c39840000303
日期:——
The rearrangement of allylicsulphinates to sulphones is facilitated by palladium catalysis, treatment of the chiral trans-and cis-allyl sulphinates (S)-(–)-(1a)-(1c), and -(1e), and(S)-(–)-(1b)and -(1d)with a catalytic amount of the palladium catalysts (3)and(5)providing the corresponding chiral allyl sulphones,(S)-(+)-and(R)-(–)-(2a–c), respectively, in good yields; exceptionally the palladium catalysis