Optically Active Biobased Hollow Polymer Particles: Preparation, Chiralization, and Adsorption toward Chiral Amines Saleem Raza, Xueyong Yong, and Jianping Deng* State Key Laboratory of Chemical Resource Engineering; College of Materials Science and Engineering, Beijing University of Chemical Technology, Beisanhuan East Road 15#, Beijing 100029, China *S Supporting Information ABSTRACT: The present work reports a new type of optically active biobased hollow polymer particles (OABHPs) starting from a commonly available biophenylpropene trans- anethole (ANE). To prepare the OABHPs, ANE and maleic anhydride (MAH) underwent precipitation copolymerization in the presence of particulate template as cores, thereby forming core/shell particles. Subsequently removing the cores provided hollow particles, which were then chiralized with chiral agents (R- and S-1-phenylethylamine) and (R- and S- cyclohexyalethylamine) to fabricate the designed OABHPs. The as-prepared particles were characterized by SEM, TEM, elemental analysis, CD, and FT-IR measurements. The chiral particles’ enantioselectivity was further explored by using them as chiral adsorbent toward D- and L-alanine and (-)-cinchonidine and (+)-cinchonine. The optically active hollow particles showed good enantiomeric excess (e.e.) toward racemic alanine. The study not only opens up a new approach for preparing chiral polymer materials, but also provides a versatile platform for making a full use of biomass to develop advanced functional materials. 1. INTRODUCTION Chiral polymer particles have been drawing much interest due to their interesting optical activity and significant applications in chiral-related areas. 1-7 In the last decades, synthetic chiral polymers have achieved remarkable progress. 8-13 More recently, chiral polymer particles and chiral hybrid particles also have demonstrated substantial applications as chiral catalysts for asymmetric catalysis, 4,14-16 chiral recognition/ adsorption, 17-19 enantioselective crystallization 20 and chiral drug release. 21,22 However, up to date most of the chiral polymer particles were constructed by chiral monomers. 23,24 It has been well recognized that chiral monomers are expensive and in particular highly limited in both varieties and number. 25,26 To solve the limitations, chiral additives, 27 chiral solvents, 28 and chiral co-monomers 29,30 were used to generate chiral polymers derived from achiral monomers via chiral induction and/or chirality transfer strategies. The present work reports a new approach for preparing chiral polymer particles starting from achiral biomass, rationally combining an idea of post-chiralization. Herein, trans-anethole (ANE) was taken as a model for biomass, as it abundantly exists in Chinese star anise, 31 fennel, 32 and anise, 33 and has been broadly used as a seasoning. Using biomass to develop chiral particles provides a significant approach toward new, green materials to use in future perspectives. 34,35 We hypothesize that hollow particles integrated with chiral moieties can be employed as high-performance adsorbents toward chiral compounds, together with other pronounced advantages. 36 In this regard, a judicious combination of biobased hollow polymer particles and chiral structures is expected to provide more promising optically active hollow particles which hopefully demonstrate both high adsorption ability and recyclability. 37,38 In our previous work, biobased hollow polymer particles (BHPs) 39 and biobased magnetic hollow particles 40 originated in trans-anethole (ANE) were prepared and used as novel bioadsorbents. Based on our earlier studies concerning chiral polymer particles 16,22,29,37 and biobased polymer particles, 39,40 we in the present work established a novel strategy for constructing optically active hollow polymer particles. Specifically, the earlier hollow particles were chiralized by a “post-chiralization” concept (Scheme 1). A new type of optically active biobased hollow particles (abbreviated as OABHPs, herein including R-PEA- HPs, S-PEA-HPs, R-CHEA-HPs, and S-CHEA-HPs), were prepared thereby. To explore their adsorption applications, the OABHPs were used as chiral adsorbent. The particles demonstrate the desired adsorption ability and enantioselec- tivity. The strategy established in the present work is expected Received: November 26, 2018 Revised: February 14, 2019 Accepted: February 20, 2019 Published: February 20, 2019 Article pubs.acs.org/IECR Cite This: Ind. Eng. Chem. Res. XXXX, XXX, XXX-XXX © XXXX American Chemical Society A DOI: 10.1021/acs.iecr.8b05884 Ind. Eng. Chem. Res. XXXX, XXX, XXX-XXX Ind. Eng. Chem. Res. Downloaded from pubs.acs.org by UNIV OF SUSSEX on 03/01/19. For personal use only.