189937-41-5Relevant academic research and scientific papers
Hybrid-Type Squaramide-Fused Amino Alcohol Organocatalysts for Enantioselective Nitro-Aldol Reaction of Nitromethane with Isatins
Chennapuram, Madhu,Subba Reddy,Seki, Chigusa,Okuyama, Yuko,Kwon, Eunsang,Uwai, Koji,Tokiwa, Michio,Takeshita, Mitsuhiro,Nakano, Hiroto
, p. 1638 - 1646 (2017/04/06)
A series of hybrid-type squaramide-fused amino alcohol (SFAA) catalysts were synthesized, and their catalytic efficiency in the enantioselective nitro-aldol reaction of various isatins with nitromethane has been described. This transformation afforded chiral 3-substituted 3-hydroxyoxindoles in excellent chemical yields (up to 99 %) with high enantioselectivities (up to 95 % ee). The resulting chiral 3-hydroxyoxindoles can be further used as synthetic precursors for the synthesis of several natural products that have a broad spectrum of fascinating biological activities.
Silyloxy Amino Alcohol Organocatalyst for Enantioselective 1,3-Dipolar Cycloaddition of Nitrones to α,β-Unsaturated Aldehydes
Otsuki, Teppei,Kumagai, Jun,Kohari, Yoshihito,Okuyama, Yuko,Kwon, Eunsang,Seki, Chigusa,Uwai, Koji,Mawatari, Yasuteru,Kobayashi, Nagao,Iwasa, Tatsuo,Tokiwa, Michio,Takeshita, Mitsuhiro,Maeda, Atushi,Hashimoto, Akihiko,Turuga, Kana,Nakano, Hiroto
, p. 7292 - 7300 (2015/11/25)
The catalytic activity of a simple amino alcohol that contains a bulky super silyl group [i.e., tris(trimethylsilyl)silyl (TTMSS)] bonded to the oxygen atom at the γ-position along with a primary amine moiety was examined in the enantioselective 1,3-dipolar cycloaddition of nitrones to α,β-unsaturated aldehydes. The organocatalyst successfully provided optically active isoxazolidines in good chemical yields (up to 86 %) with excellent diastereoselectivities (endo/exo, up to 96:4) and enantioselectivities (up to 97 % ee). Furthermore, the obtained isoxazolidines were easily converted into γ-amino diols that contain three contiguous stereogenic centers.
Synthesis of a series of novel chiral Lewis base catalysts and their application in promoting asymmetric hydrosilylation of β-enamino esters
Chen, Xing,Hu, Xiao-Yan,Shu, Chang,Zhang, Yong-Hong,Zheng, Yong-Sheng,Jiang, Yan,Yuan, Wei-Cheng,Liu, Bo,Zhang, Xiao-Mei
supporting information, p. 3089 - 3093 (2013/06/04)
A series of novel chiral Lewis base catalysts were synthesized from l-serine and applied in the hydrosilylation of β-enamino esters, in which the optimal one promoted the reactions to afford a wide variety of β-amino esters in good yields with good enantioselectivities. It is noteworthy that several cyclic substrates were hydrosilylated under the optimal conditions to give the cyclic β-amino esters with high yields, good diastereoselectivities as well as good ee values. The Royal Society of Chemistry 2013.
Design of hydrogen bond catalysts based on a modular oxazoline template: Application to an enantioselective hetero Diels-Alder reaction
Rajaram, Sridhar,Sigman, Matthew S.
, p. 5473 - 5475 (2007/10/03)
(Chemical Equation Presented) A catalyst system that displays two hydrogen bond donating arms from a rigid oxazoline backbone and its utility in a hydrogen bond promoted enantioselective hetero Diels-Alder reaction are described.
Reversal of stereochemistry in diethylzinc addition to aldehydes by a simple change of the backbone substituent in L-serine derived ligands
Sibi, Mukund P.,Chen, Jian-xie,Cook, Gregory R.
, p. 3301 - 3304 (2007/10/03)
A change in the backbone substituent from phenyl to butyl group in L- serine-derived ligands provides a simple way to prepare enantiomeric products in diethylzinc addition to aldehydes.
