Calcium-BINOL: a novel and efficient catalyst for asymmetric Michael reactions

Kumaraswamy, Gullapalli; Sastry, M. N. V.; Jena, Nivedita

doi:10.1016/s0040-4039(01)01736-1

Cited by 83 publications

(23 citation statements)

References 9 publications

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“…Ca-BINOL [36] and InCl-BINOL [37] were synthesized following literature procedures. Mg-BINOL was prepared as follows: An amount of 0.4 mmol (±)-BINOL was dissolved in 25 ml of anhydrous CH 2 Cl 2 at room temperature, and then 0.4 ml of dibutylmagnesium (1.0 M in heptane) was slowly added using an injection syringe under nitrogen.…”

Section: Preparation Of Binol Complexesmentioning

confidence: 99%

Synthesis of cyclic carbonates from epoxides catalyzed by metal–BINOL complexes

Bai

Wang

et al. 2014

Applied Organom Chemis

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Synthesis of cyclic carbonates from CO 2 and terminal epoxides catalyzed by Mg, Ca and In BINOL complexes was achieved without organic solvents. Effects of temperature, CO 2 pressure, reaction time and co-catalyst on the cycloaddition were investigated. Propylene carbonate was obtained under a CO 2 pressure of 1.2 MPa within 10 hours in a yield of 98% catalyzed by Ca-BINOL at 120°C. The order of catalytic activity of the metal center is Ca > In > Mg. Copyright © 2014 John Wiley & Sons, Ltd. Keywords: cycloaddition; epoxides; carbon dioxide; cyclic carbonate; BINOL Introduction CO 2 as a major greenhouse gas and non-toxic carbon source has received much attention in recent decades. [1][2][3] Chemical fixation of CO 2 into organic compounds is a green and atom-economic reaction. [4,5] One of the most favorable methodologies is the cycloaddition of CO 2 and epoxides to form cyclic carbonates, which are widely used as organic synthetic intermediates, aprotic polar solvents and polymerization monomers. [6][7][8][9] Many efficient catalytic systems have been developed for the synthesis of cyclic carbonates from CO 2 and epoxides. Examples include metal complexes, [10][11][12][13][14] which are some of the most efficient catalysts due to tunable structure and Lewis acidity of catalytic center among metal salts, [15][16][17][18][19] ionic liquids, [20][21][22][23][24][25][26] metal-organic frameworks [27][28][29][30][31] and N-heterocyclic carbenes. [32][33][34][35] However, many metal complexes suffer from the high toxicity transition metals and the need for an organic solvent.In order to test the catalytic activity of main group metals versus transition metals, in the study reported here, we developed simple and non-toxic Mg, Ca and In BINOL complexes as efficient catalysts for this cycloaddition to synthesize cyclic carbonates from epoxides and CO 2 without using organic solvent and under mild conditions (Scheme 1). Experimental MaterialsPropylene oxide (PO) was distilled from CaH 2 . Other epoxides were purchased from J&K and used without further purification. n-Bu 4 NF, n-Bu 4 NCl, n-Bu 4 NBr, n-Bu 4 NI, n-Bu 4 PBr and phenyltrimethylammonium tribromide (PTAT) were obtained from Aladdin. (±)-BINOL was purchased from Sinopharm Chemical Reagent Co. Ltd. General Procedure for Coupling Reaction of Epoxides and CO 2Cycloaddition of CO 2 and epoxides was performed in a 100 ml stainless steel autoclave equipped with a magnetic stir bar. The autoclave reactor was successively charged with metallic BINOL (0.05 mmol), co-catalyst (0.1 mmol) and epoxide (50 mmol). The reactor was pressurized with CO 2 to the desired pressure and then was heated and stirred at the desired temperature. When the pressure of CO 2 fell to 0.2-0.3 MPa, the reactor was cooled quickly in ice water and then slowly vented. The reaction mixture was distilled under reduced pressure or separated and purified by column chromatograph to obtain the cyclic carbonate. Preparation of BINOL ComplexesCa-BINOL [36] and InCl-BINOL [37] were synthesized following ...

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Section: Preparation Of Binol Complexesmentioning

confidence: 99%

Synthesis of cyclic carbonates from epoxides catalyzed by metal–BINOL complexes

Bai

Wang

et al. 2014

Applied Organom Chemis

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“…While chiral Brønsted base-catalyzed asymmetric transformation has been intensively explored (for reviews of asymmetric 1,4-addition reactions of 1,3-dicarbonyl compounds, see [26][27][28][29][30][31][32][33]; for reviews of asymmetric 1,4-addition reactions of glycine Schiff bases, see [34][35][36][37]; for reviews of asymmetric [3+2] cycloaddition reactions, see [38][39][40][41]), chiral alkaline-earth metal catalysts have been also successfully employed in this reaction. Kumaraswamy et al reported asymmetric 1,4-addition reactions using chiral calcium complexes prepared from calcium chloride and dipotassium salt of BINOL or H 8 [42][43][44][45]. After optimization of the calcium salts and reaction conditions, the calcium catalyst was successfully applied to asymmetric 1,4-additions of malonates or β-ketoesters to α,β-unsaturated carbonyl compounds (Tables 4 and 5) [42,44].…”

Section: Asymmetric Aldol and Related Reactionsmentioning

confidence: 99%

“…Kumaraswamy et al reported asymmetric 1,4-addition reactions using chiral calcium complexes prepared from calcium chloride and dipotassium salt of BINOL or H 8 [42][43][44][45]. After optimization of the calcium salts and reaction conditions, the calcium catalyst was successfully applied to asymmetric 1,4-additions of malonates or β-ketoesters to α,β-unsaturated carbonyl compounds (Tables 4 and 5) [42,44]. Among the α,β-unsaturated carbonyl compounds employed in the reactions with malonates, cyclopentenone was found to be a suitable substrate, and high enantioselectivities were obtained (Table 4, entries 3 and 4).…”

Section: Asymmetric Aldol and Related Reactionsmentioning

confidence: 99%

Chiral Ca-, Sr-, and Ba-Catalyzed Asymmetric Direct-Type Aldol, Michael, Mannich, and Related Reactions

Tsubogo

Yamashita

Kobayashi

2013

Alkaline-Earth Metal Compounds

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Recent progress in asymmetric direct-type aldol, Michael, Mannich, and related reactions using chiral Ca, Sr, and Ba catalysts was summarized in this chapter. Ca, Sr, and Ba are very attractive, because they are abundant and ubiquitous elements found in nature, and form relatively safe and environmentally benign compounds compared with heavy transition metals. However, their use as catalysts in asymmetric synthesis has been limited compared with that of transition metal catalysts. Their strong Brønsted basicity and mild Lewis acidity are promising and attractive characteristics, and can influence their catalytic activity as well as their chiral modification capability in a positive manner. It was revealed that several catalytic asymmetric carbon-carbon bond-forming and related reactions proceeded smoothly in high enantioselectivites using the chiral Ca, Sr, and Ba catalysts.

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“…Importantly, both enantiomers ( R and S forms) of BINOL are readily available and inexpensive. The incorporation of chiral BINOL into MOFs can prepare systems useful for asymmetric synthesis and chiral catalytic processes (Burk et al , 1991 ;Kumaraswamy et al , 2001 ;Pandiaraju et al , 2001 ;Trotta et al , 2002 ;Jayaprakash et al , 2003 ;Shibasaki and Matsunaga , 2006 ).…”

Section: Introductionmentioning

confidence: 99%

Chiral rings from BINOL dicarboxylic acids and alkane ditin(IV) linkers

Seter

Dakternieks

Duthie³

2012

Main Group Metal Chemistry

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The fi rst series of building blocks for metal-organic frameworks (MOFs) utilizing the ( S )-2,2 ′ -diethoxy-1,1 ′ -binaphthyl-6,6 ′ -dicarboxylic acid ligand linked with a number of α , ω -bis(chlorodiorganostannyl) alkane spacers and α , ω -bis(dichloroorganostannyl) alkane spacers has been synthesized and characterized. The new compounds have been shown to form monomeric chiral rings with the potential to generate large coordination networks. The potential formation of chiral supramolecular and polymeric materials from the chiral precursors was explored by investigating the structures that form as a result of the hypervalency available at metal centers. These chiral compounds were built using the concept that stemmed from the construction of MOFs. The ' pre-organized ' chiral rings synthesized here can potentially fi nd use in chiral catalysis, enantioselective synthesis and in designing chiral polymers.

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Calcium-BINOL: a novel and efficient catalyst for asymmetric Michael reactions

Cited by 83 publications

References 9 publications

Synthesis of cyclic carbonates from epoxides catalyzed by metal–BINOL complexes

Synthesis of cyclic carbonates from epoxides catalyzed by metal–BINOL complexes

Chiral Ca-, Sr-, and Ba-Catalyzed Asymmetric Direct-Type Aldol, Michael, Mannich, and Related Reactions

Chiral rings from BINOL dicarboxylic acids and alkane ditin(IV) linkers

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