- Allyl sulfones as precursors to allylzincs in the palladium-catalyzed zinc-ene cyclization: Highly efficient synthesis of enantiopure (-)-erythrodiene
-
(Chemical Equation Presented) Easily prepared allyl phenyl sulfones, capable of introduction of the alkene by electrophilic α-substitution, are superior to allyl acetates as substrates for Pd-catalyzed Zn-ene cyclizations, providing C5 or C4N r
- Deng, Kai,Chalker, Justin,Yang, Ao,Cohen, Theodore
-
p. 3637 - 3640
(2007/10/03)
-
- S(H)2' reaction in organocobaloximes: Synthesis and 1,3-rearrangement of exo-methylene alicyclic allyl sulfones
-
Photostimulated reactions of cyclopentenylmethyl-, cyclohexenylmethyl- and α-pinenyl cobaloximes with arenesulfonyl halides result in the formation of corresponding exo-methylene cycloalkylsulfones in 82-98% isolated yields. The product formation is rationalized by a radical chain mechanism involving an S(H)2' displacement of cobaloxime(II) from organocobaloximes by sulfonyl radical. Reaction under thermal condition, however, provides a mixture of exo-methylene cycloalkylsulfone and its endo-isomer. Independent experiments confirmed that the endo-isomer arises from a facile 1,3-allylic rearrangement of the exo-isomer. From mechanistic and theoretical studies the rearrangement is proposed to involve a [1,3]-sigmatropic migration of sulfonyl group.
- Roy,Das,Bhanuprakash,Gupta
-
p. 1847 - 1858
(2007/10/02)
-
- Controlled endocyclic and exocyclic-γ-metalations of β-substituted cyclohexenyl sulfones. Regiospecific syntehses of γ-oxygenated cyclohexenyl sulfones.
-
β-Substituted cyclohexenyl sulfones may be regiospecifically isomerized to either endocyclic or exocyclic allyl sulfones. Epoxidation of these materials followed by a second metalation yields γ-hydroxy cyclohexenyl sulfones 6 and 7. Subjection of either o
- lee,Fuchs
-
p. 2861 - 2864
(2007/10/02)
-
- Regioselective Preparation of Allylic Sulfones by Palladium-Catalyzed Reactions of Allylic Nitro Compounds with Sodium Benzenesulfinate
-
Treatment of allylic nitro compounds with sodium benzenesulfinate in the presence of 5 molpercent of Pd(PPh3)4 in N,N-dimethylformamide (DMF) at 20-70 deg C for 1-10 h resulted in the formation of allylic sulfones with predominance of kinetically controll
- Ono, Noboru,Hamamoto, Isami,Kawai, Takashi,Kaji, Aritsune,Tamura, Rui,Kakihana, Masato
-
p. 405 - 410
(2007/10/02)
-
- Palladium-Catalyzed Substitutions of Allylic Nitro Compounds. Regiochemistry
-
Primary, secondary, and tertiary allylic nitro compounds underwent Pd(0)-catalyzed allylic substitution by stabilized carboanions, secondary amines, and benzenesulfinate ion (PhSO2-). α,β-disubstituted α-nitro olefins also behaved as allylic nitro compounds, via base-catalyzed vinyl -> allyl rearrangement, and underwent allylic substitution by secondary amines and PhSO2-.The regiochemistry of these substitutions was dependent on the structure of the allylic nitro compound amd on the steric bulk of the nucleophile.Generally, substitution occurred at the lesshindered or least substituted site.In some cases added or generated NaNO2 affected the regioselectivity of the allylic substitution of allylic nitro compounds and some allylic acetates by PhSO2-.Under these conditions, the more sterically hindered allylic sulfones were formed.
- Tamura, Rui,Kai, Yoshiki,Kakihana, Masato,Hayashi, Koji,Tsuji, Masanori,et al.
-
p. 4375 - 4385
(2007/10/02)
-
- REGIOSELECTIVE SYNTHESIS OF ALLYLIC SULFONES BY PALLADIUM-CATALYZED DENITRO-SULFONYLATION OF ALLYLIC NITRO COMPOUNDS
-
Allylic nitro compounds undergo denitro-sulfonylation catalyzed by Pd(PPh3)4 or Pd(PPh3)4+NaNO2 with PhSO2Na*2H2O to afford allylic sulfones regioselectively.
- Tamura, Rui,Hayashi, Koji,Kakihana, Masato,Tsuji, Masanori,Oda, Daihei
-
p. 851 - 854
(2007/10/02)
-