POSS supported C2-symmetric bisprolinamide as a recyclable chiral catalyst for asymmetric Aldol reaction

Chiral catalysts immobilized on achiral polymers: effect of the polymer support on the performance of the catalyst

“…The recovery and reuse of a bisprolinamide supported on polyhedral oligomeric silsesquioxanes (POSS) for five cycles has been described through precipitation with a cosolvent and filtration. 307 The recovery efficiency was 85-92% for each individual cycle and although the enantioselectivity remained essentially constant at 93% ee, the yield decreased from 82% (1st run) to 70% (5th run). Temperature-responsive hairy polymers containing proline have been used for the direct asymmetric aldol reaction in water and a recovery 497% was obtained by centrifugation.…”

Synthesis of Silsesquioxanes with Substituted Triazole Ring Functionalities and Their Coordination Ability

“…There are some examples of CuAAC methodology applied for silsesquioxanes to introduce the triazole moiety(-ies) substituted at 1,4 positions with the SQs core and organic group. The process may be applied in the case of mono- and octa-substituted T 8 SQs, linked with the Si-O-Si core via mainly alkyl [ 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ] but there are also reports on a phenyl group [ 37 , 38 ]. There are also few examples of using di- substituted double-decker (DDSQ) [ 39 , 40 ] or ladder [ 41 ] silsesquioxanes [ 42 ].…”

“…Catalysis has become a very prospective direction of employing the SQs with 1,4-substituted triazole rings, as catalysts by themselves, e.g., in asymmetric Michael or Aldol reactions [ 32 , 33 ]. Even though there have been still very few reports in this area of interest.…”

Large Polyhedral Oligomeric Silsesquioxane Cages: The Isolation of Functionalized POSS with an Unprecedented Si18O27 Core

“…Thed evelopment of polyhedral oligomeric silsesquioxanes (POSS,R -(SiO 1.5 ) n ,w here n = 6, 8, 10, 12, etc. )i s currently an area of intense activity within the materials chemistry community,due in part to the wide range of fields in which they can be applied, including polymer chemistry, [1][2][3][4][5][6][7][8] bio/nanomedicine, [9][10][11][12][13][14] catalysis, [15][16][17][18] optical and sensing applications, [3,19,20] optoelectronics, [21] and flame retardancy. [22] Of these cage silsesquioxanes,which are composed of awelldefined (SiO 1.5 ) n polyhedral core (T n )c ovalently linked to organic moieties, [23] compounds with n = 8have been the most widely reported, studied and employed in several application fields.T hese hybrid molecules can be readily incorporated into nanostructured materials either via hydrolysis-condensation processes involving silanol groups [24] or by polymerization on the organic moiety.…”