95158-93-3Relevant academic research and scientific papers
Experimental and theoretical investigation of the enantiomerization of Lithium α-tert-butylsulfonyl carbanion salts and the determination of their structures in solution and in the crystal
Scholz, Roland,Hellmann, Gunther,Rohs, Susanne,Raabe, Gerhard,Runsink, Jan,Oezdemir, Diana,Luche, Olaf,Hess, Thomas,Giesen, Alexander W.,Atodiresei, Juliana,Lindner, Hans J.,Gais, Hans-Joachim
supporting information; experimental part, p. 4559 - 4587 (2010/10/19)
Dynamic NMR (DNMR) spectroscopy of [R1C(R2)SO 2R3]Li (R1, R2 = alkyl, phenyl; R3 = Ph, tBu, adamantyl, CEt3) in [D8]THF has shown that the S-tBu, S-adamantyl, and S-CEt3 derivatives have a significantly higher enantiomerization barrier than their S-Ph analogues. C α-S bond rotation is most likely the rate-determining step of the enantiomerization of the salts bearing a bulky group at the S atom and two substituents at the Cα atom. Ab initio calculations on [Me(Ph)- SO 2tBu]- gave information about the two Cα-S rotational barriers, which are dominated by steric effects. Cryoscopy of [R1C(R 2)SO2tBu]Li in THF at -108°C revealed the existence of monomers and dimers. X-ray crystal structure analysis of the monomers and dimers of [R1C(R2)SO2tBu]Li·L n (R1 = Me, Et, tBuCH2, PhCH2, tBu; R2 = Ph, L = THF, 12-crown-4, PMDTA) and [R1C(R 2)SO2Ph]Li·2diglyme [R1 = R2 = Me, Et; R1-R2 = (CH2)5] showed them to be O-Li contact ion pairs (CIPs). The monomers and dimers have a Cα-S conformation in which the lone-pair orbital at the Cα atom bisects the O-S-O angle and a significantly shortened Cα-S bond. The Cα atom of [R1C(R2)SO2R 3]Li·Ln (R1 = Ph; R3 = Ph, tBu) is planar, whereas the Cα atom of [R1C(R 2)SO2R3]Li·Ln (R1 = R2 = alkyl) is strongly pyramidalized in the case of R3 = Ph and most likely planar for R3 = tBu. Ab initio calculations on [MeC- (Me)SO2R]- gave a pyramidalized Cα atom for R = Me and a nearly planar one for R = CF3 and tBu. The [R1C(R 2)SO2-tBu]Li salts were characterized by 1H, 13C, and 6Li NMR spectroscopy. 1H{ 1H} and 6Li{1H} NOE experiments are in accordance with the existence of O-Li CIPs. 1H and 13C NMR spectroscopy of [R1C(R2)SO2tBu]Li in [D 8]THF at low temperatures showed equilibrium mixtures of up to five different species being most likely monomeric and dimeric O-Li CIPs with different configurations. According to 7Li NMR spectroscopy, the addition of HMPA to [MeC(Ph)SO2tBu]Li in [D8]THF at low temperatures causes the formation of the separated ion pair [MeC(Ph)SO 2tBu]Li(HMPA)4.
Reaction of α-benzenesulfonylphenylacetic acid with alkyl halides. Decarboxylative alkylation vs. decarboxylative protonation
Wladislaw, Blanka,Perna, Fernando,De Almeida Neves, Regina Maria,Marzorati, Liliana,Di Vitta, Claudio
, p. 1403 - 1409 (2007/10/03)
The reaction of α-benzenesulfonylphenylacetic acid with some alkyl halides, using as base NaH in DMSO, leads to decarboxylative protonation to give benzylphenylsulfone. Decarboxylative alkylation occurs only when CO2 is expelled by flushing with nitrogen. The mechanism of the decarboxylative protonation is investigated.
Arylmethyl phenyl sulfones, a new carbon nucleophile for Mitsunobu-type alkylation
Tsunoda, Tetsuto,Uemoto, Kaori,Ohtani, Tomoko,Kaku, Hiroto,Ito, Sho
, p. 7359 - 7362 (2007/10/03)
Cyanomethylenetrimethylphosphorane (CMMP), a new Mitsunobu reagent developed recently by the authors, mediated the alkylation of arylmethyl phenyl sulfones with primary and secondary alcohols quite efficiently. Utilizing 3-((phenylsulfonyl)methyl)pyridine
