80945-31-9Relevant academic research and scientific papers
Asymmetric catalysis on the intramolecular cyclopropanation of α-Diazo-β-keto sulfones
Honma, Masahiro,Sawada, Takashi,Fujisawa, Yuri,Utsugi, Masayuki,Watanabe, Hideaki,Umino, Akinori,Matsumura, Takehiko,Hagihara, Takayuki,Takano, Masashi,Nakada, Masahisa
, p. 2860 - 2861 (2007/10/03)
This work describes the development of a highly enantioselective asymmetric catalysis on the intramolecular cyclopropanation of α-diazo-β-keto sulfones. We have found that the catalytic asymmetric intramolecular reactions of α-diazo-β-keto sulfones generally proceed with high enantioselectivity when the α-diazo-β-keto mesityl sulfone is used with the newly prepared ligand 2e. The absolute configuration of products has been determined by X-ray crystallographic analysis, and the outcome of the enantioselectivities is explained well by our proposed models A and B. The products possess great potential for natural product synthesis because (1) many different chemistries of cyclopropane, ketone, and sulfone are available, and (2) the products are generally highly crystalline, facilitating the supplies of enantiomerically pure synthetic intermediates. Copyright
Manganese(III)-Based Asymmetric Oxidative Free-Radical Cyclization of Unsaturated β-Keto Sulfoxides
Snider, Barry B.,Wan, Barbara Yu-Fong,Buckman, Brad O.,Foxman, Bruce M.
, p. 328 - 334 (2007/10/02)
β-Keto sulfoxides and β-keto sulfones can be used as substrates for Mn(III)- and Cu(II)-based oxidative free-radical cyclizations.The sulfoxide chiral center completely controls the stereochemistry of the cyclization.Oxidative cyclization of racemic sulfo
Studies Dealing with the Alkylation--Rearrangement Reaction of Some Phenylthio-Substituted Allylic Sulfones
Padwa, Albert,Bullock, William H.,Dyszlewski, Andrew D.
, p. 955 - 964 (2007/10/02)
A series of 2-(phenylthio)-3-(phenylsulfonyl)alkenes are easily metalated with n-butyllithium, and the resulting carbanion is regioselectively alkylated by alkyl halides in the α-position to give β,γ-unsaturated sulfones in high yield.These substituted ph
Carbanion-Accelerated Claisen Rearrangements. 6. Preparative and Stereochemical Studies with Sulfonyl-Stabilized Anions
Denmark, Scott E.,Harmata, Michael A.,White, Kathleen S.
, p. 8878 - 8891 (2007/10/02)
The aliphatic Claisen rearrangement is markedly accelerated by an arylsulfonylmethide substituent at position 2.The generality of this anion variant has been extensively examined (31 allyl vinyl ethers) with regard to substitution, stereochemistry, and an
ALLYLIC 1,3-REARRANGEMENT OF THIOPHENYL SUBSTITUTED SULFONES
Padwa, Albert,Bullock, William H.,Dyszlewski, Andrew D.
, p. 3193 - 3196 (2007/10/02)
Substituted thiophenyl allyl sulfones undergo a 1,3-allylic sulfonyl shift and this rearrangement has been utilized within a metallation-alkylation sequence.
CYCLOPENTANATION WITH β-METHYLTHIO-ALLYL PHENYL SULFONE
Barre, V.,Uguen, D.
, p. 6045 - 6048 (2007/10/02)
The allylic thiosulfones 2 resulting from the addition of thiols to propargylic sulfone 1 have been used to convert enones into diketo-sulfones which then led to bicyclo alkanediones by either tris-anionization then cupric oxidation or treatment with rhodium acetate of the corresponding diazoketo-sulfone.
Silicon-Assisted Ring Opening of Cyclopropyl Ketones with Boron Trifluoride-Acetic Acid Complex
Ochiai, Masahito,Sumi, Kenzo,Fujita, Eiichi
, p. 3931 - 3938 (2007/10/02)
2-(Trimethylsilylmethyl)cyclopropyl ketones were smoothly cleaved with boron trifluoride-acetic acid complex under mild reaction conditions with the assistance of the trimethylsilyl group to give γ,δ-enones in good yields.The major effect of the trimethylsilyl group in the ring opening of the cyclopropyl ketones was unambiguously confirmed in the dicyclopropyl ketone 15: one of its two cyclopropyl rings, which has a trimethylsilylmethyl group, was selectively cleaved.Furthermore, the reaction was applied to the formal total synthesis of cis-jasmone.Keywords - ring opening of cyclopropyl ketone; trimethylsilyl group; γ,δ-enone; cis-jasmone; allylsilane; boron trifluoride-acetic acid
RING OPENING OF CYCLOPROPYL KETONES ASSISTED BY THE TRIMETHYLSILYL GROUP
Ochiai, Masahito,Sumi, Kenzo,Fujita, Eiichi
, p. 79 - 80 (2007/10/02)
Cyclopropyl ketones 2 were smoothly cleaved with boron trifluoride-acetic acid under mild reaction conditions by the assistance of trimethylsilyl group to give γ,δ-enones in good yields and the reaction was applied to the formal total synthesis of cis-jasmone.
