Entropy-Controlled Asymmetric Catalysis

Sohtome, Yoshihiro; Shin, Bongki; Horitsugi, Natsuko; Takagi, Rika; Noguchi, Koto; Nagasawa, Kazuo

doi:10.1055/s-0030-1258781

Cited by 17 publications

(67 citation statements)

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“…Inspired by the early work by Chen, 23 they initially developed the Friedel-Crafts (FC) reaction of 14 with 15 using (S,S)-16, as shown in the first process in Scheme 1. 22,24 The chemo-, regio-, and enantioselectivity achieved even in the presence of multiple reactive sites in the FC-adduct 17 is remarkable (66-99% yield, 82-94% ee). The selectivity may be a consequence of 14 were proposed.…”

Section: Programmed Organocascadesmentioning

confidence: 98%

Sequential stereodivergent organocatalysis and programmed organocascades

Sohtome

Nagasawa

2014

Org. Biomol. Chem.

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Asymmetric organocatalysis has attracted great interest as a synthetic strategy during the past decade. But, although the inertness of organocatalysts to moisture and oxygen offers great opportunities to tune the reaction conditions, the stereoswitchable character of organocatalysts has not been systematically studied, and most findings have been serendipitous. In this Perspective, we emphasize the importance of in situ tunability in dynamic asymmetric organocatalysis for obtaining different functional outcomes with single-flask operation.

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Section: Programmed Organocascadesmentioning

confidence: 98%

Sequential stereodivergent organocatalysis and programmed organocascades

Sohtome

Nagasawa

2014

Org. Biomol. Chem.

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“…In the case of a phenyl group at R 3 , selectivity was similar to that with 3 a , but the yield was decreased to 55 % (Table 2, entry 5). The effects of the R 1 and R 2 groups in catalyst 3 were also examined 8f,h. Interestingly, selectivity was drastically reduced with 3 f – 3 h bearing disubstituted guanidines, even though R 3 was a benzyl group, and almost racemic 5 a was obtained (Table 2, entries 6–8).…”

Section: Resultsmentioning

confidence: 99%

Asymmetric α‐Hydroxylation of Tetralone‐Derived β‐Ketoesters by Using a Guanidine–Urea Bifunctional Organocatalyst in the Presence of Cumene Hydroperoxide

Odagi

Furukori

Watanabe

et al. 2013

Chemistry A European J

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Highly enantioselective catalytic oxidation of 1-tetralone-derived β-keto esters was achieved by using a guanidine-urea bifunctional organocatalyst in the presence of cumene hydroperoxide (CHP), a safe, commercially available oxidant. The α-hydroxylation products were obtained in 99% yield with up to 95% enantiomeric excess (ee). The present oxidation was successfully applied to synthesize a key intermediate of the anti-cancer agent daunorubicin (2).

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“…In 2010, Sohtome and co‐workers reported an efficient conformationally flexible organocatalysts . They prepared chiral C3‐connected guanidine/bisthiourea 139 .…”

Section: Organocatalyzed Asymmetric Friedel‐crafts Reactions Usingmentioning

confidence: 99%

“…For nitroalkene 134 g bearing a bulky aliphatic group at the β position, a higher amount catalyst is required. In addition to phenols, 2‐naphthol and 1‐naphthol were also employed in this catalyzed AF‐CA reaction to give the corresponding products 140 in 82–93 % enantioselectivities and 77–99 % chemical yields (Scheme , Table ) …”

Section: Organocatalyzed Asymmetric Friedel‐crafts Reactions Usingmentioning

confidence: 99%

Organocatalyzed Asymmetric Friedel‐Crafts Reactions: An Update

Heravi

Zadsirjan

Heydari

et al. 2019

The Chemical Record

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The Friedel‐Crafts alkylation (F‐CA) reaction is a special kind of carbon−carbon bond formations, which is frequently being used for the formation of such bond in some aromatic rings in organic synthesis. Its asymmetric variant gives enantiorich products. Commonly, an in situ organocatalyzed asymmetric Friedel‐Crafts alkylation (AF‐CA) proceeds via generation of an enamine as an intermediate. The organocatalyzed‐AF‐CA was discovered and established in the mid‐1980s and reviewed comprehensively in 2010. In this report, we are trying to update the applications of novel organocatalysts in the AF‐CA as a versatile synthetic strategy, which is frequently used in the effective asymmetric synthesis of complex molecules, pharmaceutically important compounds and most importantly in the total synthesis of biologically active natural products.

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Entropy-Controlled Asymmetric Catalysis

Cited by 17 publications

References 0 publications

Sequential stereodivergent organocatalysis and programmed organocascades

Sequential stereodivergent organocatalysis and programmed organocascades

Asymmetric α‐Hydroxylation of Tetralone‐Derived β‐Ketoesters by Using a Guanidine–Urea Bifunctional Organocatalyst in the Presence of Cumene Hydroperoxide

Organocatalyzed Asymmetric Friedel‐Crafts Reactions: An Update

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