Enantioselective Synthesis of β‐Nitrophosphonates Using Immobilized Quinine Organocatalyst on Mesoporous SBA‐15 as an Efficient Recyclable Catalyst. Issue 25 (6th July 2018)

• Record Type: Journal Article
• Authors: Nazish, Mohd; Kumar, Gaurav; Tak, Rajkumar; Khan, Noor‐ul H.; Kureshy, Rukhsana I.
• Is Part Of: ChemistrySelect. Volume 3:Issue 25(2018)
• Page Start: 7394
• Page End: 7401
• Publication Date: 2018-07-06
• Subjects: β-nitro phosphonates -- diphenylphosphite -- enantioselectivity -- organocatalyst -- Qn-SBA-15; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201801525
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: Quinine (QN) organocatalyst immobilized on mesoporous SBA‐15 was synthesized by radical polymerization method. The characterization of the synthesized heterogeneous organocatalystQN‐SBA‐15 (4 b ) was accomplished by various physico‐chemical methods to confirm the successful loading of quinine organocatalyst over SBA‐15 material. The heterogeneous organocatalyst4 b was used for asymmetric Michael addition of diphenylphosphite to nitroalkenes. In contrast to its homogeneous analogue, the catalytic activity of4 b was significantly improved as revealed by high enantioselectivity (98%) and yield (92%) of β‐nitro phosphonates when molecular sieve was used as an additive. Moreover, the catalyst was recyclable for five cycles with retention of enantioselectivity and yield. Abstract : Heterogeneous catalyst QN‐SBA‐15 (4 b ) i. e. Quinine (QN) loaded on SBA‐15 was successfully synthesized, characterized and explored for the enantioselective 1, 4 addition of diphenylphosphite to nitroalkenes. The confined medium effect of mesoporous material was observed delivering precursor for β‐amino Phosphonic acid in good yield and good ee up to 98%. The catalyst was recyclable up to five catalytic cycle.