Catalytic asymmetric epoxidation of non-functionalised alkenes using polymeric Mn(III) Salen as catalysts and NaOCl as oxidant

Kureshy, Rukhsana I.; Khan, Noor‐ul H.; Abdi, Sayed H. R.; Singh, Surendra; Ahmed, Irshad; Jasra, Raksh V.

doi:10.1016/j.molcata.2004.03.043

Cited by 40 publications

(24 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In general it is observed that coordinating solvents have greater effects on catalytic activity, which is expected due to their inherent nature of blocking one or more coordination sites. 21,22 However, in the present study, CH 3 CN has an adverse effect on epoxidation as more benzaldehyde is formed (10% of yield with 55% chemo-selectivity; …”

Section: Effect Of Solventcontrasting

confidence: 50%

“…21,22 Therefore, the effects of different media, like polar media (e.g. with CH 3 OH as solvent), non-polar media (e.g.…”

Section: Effect Of Solventmentioning

confidence: 99%

“…molecular O 2 ). 21,22 When molecular O 2 and H 2 O 2 were used as oxidants, the reaction did not proceed at all, and in the case of PhIO, the reaction did not proceed to give desired product epoxide (Table 1, entry 6), whereas, in the case of TBHP, which is a peroxide with a stronger peroxide linkage, the first step involved is formation of metal peroxo complex, followed by M O species, which is basically the active intermediate in catalytic cycle. Thus, TBHP is the most effective oxidant, as it was found to be more selective towards epoxide formation (Table 1, entry 1).…”

Section: Effect Of Oxidantmentioning

confidence: 99%

“…The new band disappears after 1 h and the color of the solution changes back to original yellow, indicating regeneration of the catalyst. Kureshy et al 21,22 and Groves et al 24,25 have reported the formation of a carbocation or free radical intermediate to be largely responsible for formation of an aldehyde and racemization of the chiral product. Hence, in the present study, the formation of aldehyde and poor enantioselectivity is observed, probably due to formation of either cationic or radical intermediate or lack of coordination of the substrate during catalytic cycle (Scheme 2).…”

Section: Catalytic Mechanismmentioning

confidence: 99%

See 3 more Smart Citations

Synthesis and catalytic activity of binuclear Mn(III, III)–BINOL complexes for epoxidation of olefins

Patel

Trivedi

2006

Appl. Organometal. Chem.

View full text Add to dashboard Cite

The novel binuclear complexes [Mn (III,III) 2 (BINOL) 3 L 2 ]2H 2 O, where, L = 2, 2 -bipyridine (Bpy) or 1,10-phenanthroline (Phen) and BINOL = 1, 1 -bi-2-naphthol were synthesized and characterized by elemental analyses, magnetic susceptibility and various spectral methods. The catalytic activity of these complexes was studied for the epoxidation reaction of unfunctionalized olefins like styrene, 1-hexene, 1-octene and 1-decene. The products thus obtained were analyzed by GC. The epoxidation reactions were carried out, in the presence of catalyst with different oxidants, to study the effect of the nature of the oxidant on the reactions. The different oxidants used were the peroxide oxygen donor (e.g. TBHP and H 2 O 2 ), mono oxygen donor (e.g. PhIO) and dioxygen donor (e.g. molecular O 2 ). TBHP was found to be the best oxidant for the epoxidation reaction. To study the effect of the solvent on the epoxidation, the reactions were carried out in different media, such as a polar media (e.g. with CH 3 OH as solvent), non-polar media (e.g. with CH 2 Cl 2 and C 6 H 6 as solvents) and coordinating solvent (e.g. CH 3 CN). The maximum epoxide formation was observed in CH 2 Cl 2 medium. The epoxidation reactions with optically active BINOL catalysts under optimum established conditions were carried out to examine the enantioselectivity of the catalysts. The complexes were, however, found not to be enantioselective.

show abstract

Section: Effect Of Solventcontrasting

confidence: 50%

“…21,22 Therefore, the effects of different media, like polar media (e.g. with CH 3 OH as solvent), non-polar media (e.g.…”

Section: Effect Of Solventmentioning

confidence: 99%

Section: Effect Of Oxidantmentioning

confidence: 99%

Section: Catalytic Mechanismmentioning

confidence: 99%

See 2 more Smart Citations

Synthesis and catalytic activity of binuclear Mn(III, III)–BINOL complexes for epoxidation of olefins

Patel

Trivedi

2006

Appl. Organometal. Chem.

View full text Add to dashboard Cite

show abstract

“…[32][33][34][35] As chiral catalysts are expensive, their reusability is highly advantageous during industrial application. With our continuing efforts towards the development of recyclable dimeric/polymeric catalysts [36][37][38][39] for various asymmetric organic transformations, we are extending the application of polymeric salen ligand 39 for the synthesis of new polymeric zinc salen complex as an effective catalyst for enantioselective phenylacetylene addition to aldehydes and ketones to synthesize corresponding chiral secondary and tertiary propargylic alcohols in single step. High yields (up to 96%) with 72% enantioselectivity at room temperature were achieved.…”

Section: Introductionmentioning

confidence: 99%

Enantioselective phenylacetylene addition to aldehydes and ketones catalyzed by recyclable polymeric Zn(salen) complex

et al. 2006

View full text Add to dashboard Cite

New polymeric Zn(salen) complex was employed in the enantioselective phenylacetylene addition to aldehydes and ketones to produce corresponding chiral secondary propargylic alcohols with yields (up to 96%) and enantioselectivity (up to 72%) and tertiary propargylic alcohols with yields (up to 79%) and enantioselectivity (up to 68%) at room temperature, with added advantage of four times reuse with retention of enantioselectivity.

show abstract

An Overview of Polymer‐Immobilized Chiral Catalysts and Synthetic Chiral Polymers

Itsuno

2011

Polymeric Chiral Catalyst Design and Chiral Polymer Synthesis

View full text Add to dashboard Cite

Catalytic asymmetric epoxidation of non-functionalised alkenes using polymeric Mn(III) Salen as catalysts and NaOCl as oxidant

Cited by 40 publications

References 24 publications

Synthesis and catalytic activity of binuclear Mn(III, III)–BINOL complexes for epoxidation of olefins

Synthesis and catalytic activity of binuclear Mn(III, III)–BINOL complexes for epoxidation of olefins

Enantioselective phenylacetylene addition to aldehydes and ketones catalyzed by recyclable polymeric Zn(salen) complex

An Overview of Polymer‐Immobilized Chiral Catalysts and Synthetic Chiral Polymers

Contact Info

Product

Resources

About