1233346-35-4Relevant academic research and scientific papers
Catalytic Asymmetric Iterative/Domino Aldehyde Cross-Aldol Reactions for the Rapid and Flexible Synthesis of 1,3-Polyols
Lin, Luqing,Yamamoto, Kumiko,Mitsunuma, Harunobu,Kanzaki, Yamato,Matsunaga, Shigeki,Kanai, Motomu
, p. 15418 - 15421 (2015)
We report here catalytic asymmetric iterative and domino cross-aldol reactions between aldehydes, endowed with a high level of robustness, flexibility, and generality. A Cu(I)-DTBM-SEGPHOS complex catalyzes an asymmetric cross-aldol reaction between acceptor aldehydes and boron enolates derived from donor aldehydes, which are generated through Ir-catalyzed isomerization of allyloxyboronates. The unit process can be repeated using the aldol products in turn as acceptor substrates for the subsequent asymmetric aldol reaction. The donor aldehydes and stereoselectivity can be flexibly switched in a stepwise manner for the double-aldol reaction. Furthermore, asymmetric triple- and quadruple-aldol reactions are possible in one-pot using the appropriate amounts of donors and amine additives, rapidly elongating the carbon skeleton with controlling up to eight stereocenters. The method should be useful for straightforward synthesis of enantiomerically and diastereomerically enriched 1,3-polyols.
Chiral primary amine organocatalysts for syn-selective asymmetric cross-aldol reactions
Gao, Qiang,Liu, Yan,Lu, Shengmei,Li, Can
experimental part, p. 899 - 903 (2012/06/18)
Based on the "acid-base" interaction strategy, organocatalysts for the asymmetric cross-aldol reaction were synthesized by the in situ combination of chiral primary amines with protonic acids. Unlike general secondary amine catalysts that give anti-selective products, as-prepared primary amine catalysts can give syn-selective cross-aldol products with high yield and high selectivity (up to 90 yield, 90:10 syn/anti ratio, 90 ee). Compared with the complex synthesis of the reported catalysts, the primary amine catalyst that gave the best results was easily prepared using commercial available (1S,2S)-(+)-cyclohexanediamine.
Chiral Primary Amine Organocatalysts for Syn-selective Asymmetric Cross-Aldol Reactions
Gao, Qiang,Liu, Yan,Lu, Shengmei,Li, Can
, p. 899 - 903 (2016/04/10)
Based on the "acid-base" interaction strategy, organocatalysts for the asymmetric cross-aldol reaction were synthesized by the in situ combination of chiral primary amines with protonic acids. Unlike general secondary amine catalysts that give anti-selective products, as-prepared primary amine catalysts can give syn-selective cross-aldol products with high yield and high selectivity (up to 90% yield, 90:10 syn/anti ratio, 90% ee). Compared with the complex synthesis of the reported catalysts, the primary amine catalyst that gave the best results was easily prepared using commercial available (1S,2S)-(+)-cyclohexanediamine.
Chiral primary-tertiary diamine-bronsted acid salt catalyzed syn-selective cross-aldol reaction of aldehydes
Li, Jiuyuan,Fu, Niankai,Li, Xin,Luo, Sanzhong,Cheng, Jin-Pei
experimental part, p. 4501 - 4507 (2010/10/04)
(Figure presented) Highly syn-selective cross-aldol reaction of aldehydes has remained a challenging subject in the field of aminocatalysis. To achieve this end, chiral primary amines have been explored and the primary-tertiary diamine-Bronsted acid salts are found to promote the cross-aldol reactions of aldehydes with high activity and syn selectivity. Among various vicinal diamines screened, l-phenylalanine derived 2a/TfOH conjugate is identified as the optimal catalyst, showing good catalytic activity (up to 97% yield) and high syn selectivities (syn/anti up to 24:1, 87% ee). The current catalysis works selectively with small aliphatic aldehydes donors such as propionaldehyde and isobutyraldehyde, but not with aliphatic aldehydes bearing larger β-substitute (>Me). In addition, the use of 2a/TfOH conjugate has also enabled the first syn-selective cross-aldol reactions of glycoaldehyde donors.
