40847-09-4Relevant articles and documents
Novel poly(2-oxazoline)s with pendant l-prolinamide moieties as efficient organocatalysts for direct asymmetric aldol reaction
Wang, Yao,Shen, Huifang,Zhou, Le,Hu, Fangyu,Xie, Shoulei,Jiang, Liming
, p. 6739 - 6749 (2016/09/03)
Poly(2-oxazoline)-supported bifunctional organocatalysts have been prepared through a bottom-up protocol, which involves synthesis of well-defined poly(2-oxazoline) precursors bearing amino groups in the side-chains followed by amide coupling with N-Boc-l-proline then deprotection. The resultant l-prolinamido-functionalized polymers have proven to be significantly more active than their monomeric counterparts for the aldolisation of cyclic ketones with several substituted benzaldehydes under neat conditions. By using 15 mol% of the polymer as a catalyst, the direct aldol reaction products were isolated in high yields and with good diastereo- and enantioselectivity. Based on circular dichroism spectrum analysis, the enhancement in catalytic activity is probably related to the conformational changes of the pseudo-peptide scaffold of poly(2-oxazoline)s. In addition, these soluble polymeric catalysts can be recovered and reused by precipitation in ether for five catalytic cycles without significantly diminishing their efficiency.
Chiral primary-tertiary diamine catalysts derived from natural amino acids for syn-aldol reactions of hydroxy ketones
Li, Jiuyuan,Luo, Sanzhong,Cheng, Jin-Pei
supporting information; experimental part, p. 1747 - 1750 (2009/08/07)
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