Highly efficient synthesis of functionalized tertiary alcohols catalyzed by potassium alkoxide–crown ether complexes

Hatano, Manabu; Suzuki, Shinji; Takagi, Erina; Ishihara, Kazuaki

doi:10.1016/j.tetlet.2009.01.028

Cited by 27 publications

(14 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…C was effective in 1,2-hydrophosphonylation of benzalacetones (7) and dimethyl phosphite (2b). Both aromatic and heteroaromatic benzalacetones 7 were acceptable, and the corresponding novel optically active tertiary allylic alcohols (8a-g) were obtained with good to high enantioselectivities without the possible phospha-Brook rearrangement and/or retro-reaction [49][50][51]. The products were highly crystalline, and recrystallization from ethanol increased the optical purity (91~>99% ee) without any serious loss of yield.…”

Section: Catalytic Enantioselective Addition Of Phosphorus Nucleophilmentioning

confidence: 98%

Brønsted Acid/Lewis Base Hybrid Complexes

Hatano

Ishihara

2015

Topics in Organometallic Chemistry

Self Cite

View full text Add to dashboard Cite

Recent progress on our Brønsted acid/Lewis base hybrid complexes in some asymmetric catalyses is reviewed. Based on the rational design of conjugated acid-base catalysts, tailor-made supramolecular catalysts can show remarkable catalytic activity and higher-ordered selectivities that cannot be realized by ready-made single-molecule catalysts. The chiral supramolecular magnesium(II) binaphtholate complexes trigger the highly enantioselective 1,4-hydrophosphinylation and 1,2-hydrophosphonylation of α,β-unsaturated carbonyl compounds, direct Mannichtype reaction, and hetero-Diels-Alder reaction. Moreover, the advanced supramolecular catalysts are prepared in situ from chiral 3,3 0 -disubstituted binaphthols and biphenols, arylboronic acid, and B(C 6 F 5 ) 3 , for promoting the anomalous endo-/ exo-selective Diels-Alder reaction. The specific mechanism and deep insights into the possible key intermediates are discussed on the basis of rational design of chiral supramolecular Brønsted acid/Lewis base hybrid catalysts as artificial enzymes.

show abstract

Section: Catalytic Enantioselective Addition Of Phosphorus Nucleophilmentioning

confidence: 98%

Brønsted Acid/Lewis Base Hybrid Complexes

Hatano

Ishihara

2015

Topics in Organometallic Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

“…Even with 0.5 mol% of catalyst 70, a desired product was obtained in excellent yield (97%) (124). Later, the authors further developed a highly efficient Mukaiyama aldol reaction between ketones and trimethylsilyl enolates in the presence of catalytic potassium alkoxidecrown ether complexes, which gave the desired products in excellent yields (>99% yield in most cases) (125).…”

Section: Main Group Metals-base Catalystsmentioning

confidence: 99%

Aldol Reaction—Homogeneous

Cai

2011

Encyclopedia of Catalysis

View full text Add to dashboard Cite

The aldol reaction is one of the oldest and important methods for the construction of carbon–carbon bonds in organic chemistry. Over the last 30 years, tremendous efforts have resulted in the development of many highly sophisticated and efficient catalytic methods of modern aldol reactions in catalytic chemo‐, regio‐, enantio‐, and diastereoselective manners. This review outlined those efforts in homogeneous catalysis and discussed with selected examples (331 publications) according to the different elemental types of catalysts, for example, transition metals and rare earth metals based Lewis acids, main group metals based catalysts, multifunctional catalysts, and metal‐free catalysts.

show abstract

“…[7] However,t heir reactivity has been poorly explored, probably because of al acko fg eneral and direct methods for their synthesis. [8] Recently,w er eported the direct synthesis of these highly functionalized compounds through the nucleophilic addition of bis-(trimethylsilyl)ketene acetals to propargyl ketones activated by BF 3 ·Et 2 O. [9] We showed that b-hydroxy-g-alkynoic acids can react regioselectively with N-bromosuccinimide to give 5-bromo-3,4-dihydro-2 H-pyran-2-ones 3 (6-endo-dig product, Scheme 1).…”

Section: Introductionmentioning

confidence: 99%