- Lewis Base/Br?nsted Acid Co-catalyzed Enantioselective Sulfenylation/Semipinacol Rearrangement of Di- and Trisubstituted Allylic Alcohols
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An enantioselective sulfenylation/semipinacol rearrangement of 1,1-disubstituted and trisubstituted allylic alcohols was accomplished with a chiral Lewis base and a chiral Br?nsted acid as cocatalysts, generating various β-arylthio ketones bearing an all-carbon quaternary center in moderate to excellent yields and excellent enantioselectivities. These chiral arylthio ketone products are common intermediates with many applications, for example, in the design of new chiral catalysts/ligands and the total synthesis of natural products. Computational studies (DFT calculations) were carried out to explain the enantioselectivity and the role of the chiral Br?nsted acid. Additionally, the synthetic utility of this method was exemplified by an enantioselective total synthesis of (?)-herbertene and a one-pot synthesis of a chiral sulfoxide and sulfone.
- Xie, Yu-Yang,Chen, Zhi-Min,Luo, Hui-Yun,Shao, Hui,Tu, Yong-Qiang,Bao, Xiaoguang,Cao, Ren-Fei,Zhang, Shu-Yu,Tian, Jin-Miao
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p. 12491 - 12496
(2019/08/16)
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- ENANTIOCONTROLLED SYNTHESES OF THE CUPARENE SESQUITERPENES, (-)-HERBERTENE, (+)-β-CUPARENONE, (-)-DEBROMOAPLYSIN, AND (-)-APLYSIN
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Enantiocontrolled syntheses of the Cuparene sesquiterpenes, (-)-herbertene, (+)-cuparenone, (-)-debromoaplysin, and (-)-aplysin, have been achieved starting from the optically active tricyclic dienone by employing a Fischer indolization reaction under non-acidic conditions as the key step.
- Takano, Seiichi,Moriya, Minoru,Ogasawara, Kunio
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p. 329 - 332
(2007/10/02)
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- Structures of ent-Herbertane Sesquiterpenoids displaying Antifungal Properties from the Liverwort Herberta adunca
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Several aromatic sesquiterpenoids displaying antifungal propaerties have been isolated from the liverwort Herberta adunca together with a mother hydrocarbon with a novel irregular sesquiterpene skeleton, ent-herbertane, and their structures and absolute configurations have been determined on the basis of extensive degradation reactions and spectroscopic evidence.The biological activity is also described.
- Matsua, Akihiko,Yuki, Shunji,Nakayama, Mitsuru
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p. 701 - 710
(2007/10/02)
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