Highly enantioselective addition of (S)-lithiomethyl 1-naphthyl sulfoxide to ketones

Sakuraba, Hidetake; Ushiki, Shigeru

doi:10.1016/s0040-4039(00)98069-9

Cited by 43 publications

(19 citation statements)

References 13 publications

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“…49 The Knovenagel condensation has been carried out diastereoselectively 50 ' 51 and enantioselectively. 52 ' 53 Dilithio Nmethaiesulfinyl-p-toluidine, 5 4 tosylmethylisocyanide 5 5 , a-methoxyvinyllithium, 5 6 lithiated allylic carbamate, 57 and lithium bis(ethylenedioxyboryl)methide 58 have been employed as catalysts in the modified version of this reaction. Recently, antimony based in situ generated catalysts have been used to successfully alkylidenate steroidal ketones.…”

Section: Resultsmentioning

confidence: 99%

Chemistry, Biochemistry, Pharmacology, and Toxicology of CS and Synthesis of Its Novel Analogs

Munavalli¹,

Rohrbaugh²,

Durst³

2007

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Section: Resultsmentioning

confidence: 99%

Chemistry, Biochemistry, Pharmacology, and Toxicology of CS and Synthesis of Its Novel Analogs

Munavalli¹,

Rohrbaugh²,

Durst³

2007

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“…In two selected cases (type I: 3 + PhCHO; type II: 4 + Ph 2 CO) it has been shown that only the S S R C /R S S C diastereomers were formed and not the S S S C /R S R C diastereomers. The stereoselection of analogous reactions (lithiated methyl 1-naphtyl sulfoxide with aromatic ketones) has been traced back to stabilizing π⋯π interactions between the aromatic rings 26 which might also be the case in the systems described here. On the other hand, the combination of both a chiral α-C atom and a chiral electrophile led to the formation of three stereogenic centers and to de values between 14 and 62% only.…”

Section: Conclusion and Summarymentioning

confidence: 90%

“…[13][14][15][16][17] Thus, Durst et al found that methylation and deuteration of lithiated sulfoxides proceeded with good diastereoselectivities. 18,19 On the basis of these and further findings, [20][21][22][23][24][25][26][27][28][29][30][31] it was stated that the diastereofacial differentiation in reactions of α-sulfinyl functionalized alkyl aryl lithium compounds is determined by the chiral sulfinyl group as follows: electrophiles with an oxygen-containing group like D 2 O, benzaldehyde, benzophenone or CO 2 tend to attack the anionic C atom on the side of the S-O bond due to an attractive interaction of the electrophile with the countercation Li + . In the case of CH 3 I the electrophile approaches from the opposite side, because of the lack of an attractive interaction with the countercation Li + as shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

Lithiated sulfoxides: α-sulfinyl functionalized carbanions

et al. 2015

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Reactions of alkyl aryl sulfoxides H-CRR'S(O)Ar with n-BuLi-TMEDA (TMEDA = N,N,N',N'-tetramethylethylenediamine) afforded α-sulfinyl functionalized alkyl aryl lithium compounds of the type [Li2{CRR'S(O)Ar}2(TMEDA)2] (1, R/R' = H/H, Ar = Ph; 2, R/R' = H/H, Ar = p-Tol; 3, R/R' = Me/Me, Ar = Ph; 4, R/R' = H/Ph, Ar = Ph; 5, R/R' = Me/Ph, Ar = Ph). The compounds were characterized by (1)H, (13)C and (7)Li NMR spectroscopy and, except for 5, by single-crystal X-ray diffraction analyses. In crystals of 1, 2, 3 and 4 ·Et2O dinuclear molecules with four-membered Li2O2 rings were found. There are no LiCα contacts, thus, "free" carbanions are the main structural feature. Reactions of 1-6 (6, R/R' = H/Me, Ar = Ph) with benzaldehyde and benzophenone afforded the corresponding sulfoxides of the type ArS(O)CRR'CHPhOH (1a-6a) and ArS(O)CRR'CPh2OH (1b-6b), respectively. The reactions yielding / and / proceeded with high diastereoselectivities. By X-ray diffractometry it has been shown that in the case of and the diastereomers consisting of the two enantiomers SSRC and RSSC were formed.

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“…Similar phenomena have been reported in oxidations in crystalline complexes. 35 The reactions of other aryloxyepoxides were affected by the presence of β -CD to proceed regioselectively. 36 halohydrins has been carried out with hydrogen and lithium halides in the presence of β -CD.…”

Section: Ring Opening Reactionsmentioning

confidence: 99%

Reactions Mediated by Cyclodextrins

Takahashi

2010

Molecular Encapsulation

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IntroductionCyclodextrins (CDs) are naturally occurring torus -shaped molecules composed of 6, 7, or 8 D -glucose units. A fascinating property of CDs is their ability to incorporate other organic compounds into their cavities in aqueous solution. 1 Since their discovery, CDs have served as prototypes for novel host compounds and catalysts. The use of CDs as microvessels to perform chemical reactions has attracted the interest of chemists since the 1960s. 2 Effects of CDs on reactions are mainly divided into two categories. The fi rst effect is the catalytic effect, designated as the ' enzyme model. ' CD and the reactant initially form a CD -reactant reaction intermediate involving a covalent bond, which then proceeds to product. The second effect does not involve a covalent bond. The cavity of CD presents a new reaction environment to the reactant, an ' extra reaction fi eld ' , in which the reactivity, such as rate or selectivity, changes. In these cases, the role of the CD does not always catalyze, but mediates the reaction. The CD cavity is less polar than the bulk aqueous medium. The permittivity in the CD cavity is known to be nearly the same as that of dioxane. The microenvironment around the reactant in the CD cavity is different from that in the reaction media. Three distinct microenvironmental effects are expected: a) microsolvent effects, b) the protection of unstable intermediates or products, and c) the solubilization of the reactant. In addition, conformational effects can also be expected: Molecular Encapsulation: Organic Reactions in Constrained SystemsEdited by Udo H. Brinker and Jean-Luc Mieusset

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Highly enantioselective addition of (S)-lithiomethyl 1-naphthyl sulfoxide to ketones

Cited by 43 publications

References 13 publications

Chemistry, Biochemistry, Pharmacology, and Toxicology of CS and Synthesis of Its Novel Analogs

Chemistry, Biochemistry, Pharmacology, and Toxicology of CS and Synthesis of Its Novel Analogs

Lithiated sulfoxides: α-sulfinyl functionalized carbanions

Reactions Mediated by Cyclodextrins

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