7218-27-1Relevant articles and documents
A "traceless" Directing Group Enables Catalytic SN2 Glycosylation toward 1,2- cis-Glycopyranosides
Fu, Yue,Liu, Peng,Ma, Xu,Zhang, Liming,Zheng, Zhitong,Zhu, Xijun
supporting information, p. 11908 - 11913 (2021/08/20)
Generally applicable and stereoselective formation of 1,2-cis-glycopyranosidic linkage remains a long sought after yet unmet goal in carbohydrate chemistry. This work advances a strategy to this challenge via stereoinversion at the anomeric position of 1,2-trans glycosyl ester donors. This SN2 glycosylation is enabled under gold catalysis by an oxazole-based directing group optimally tethered to a leaving group and achieved under mild catalytic conditions, in mostly excellent yields, and with good to outstanding selectivities. The strategy is also applied to the synthesis of oligosaccharides.
Derivatives and application to the asymmetric synthesis of unnatural α-amino acid derivative
Inokuma, Tsubasa,Jichu, Takahisa,Nishida, Kodai,Shigenaga, Akira,Otaka, Akira
, p. 573 - 581 (2017/06/07)
We describe herein a manganese(IV) oxide-mediated oxidation of N-p-methoxyphenyl (PMP)-protected glycine derivatives for the synthesis of a-imino carboxylic acid derivatives. Using this methodology, utilization of unstable glyoxic acid derivatives was avoided. Furthermore, using this methodology we synthesized novel a-imino carboxylic acid derivatives such as a-imino phenyl ester, perfluoroalkyl etsers, imides, and thioester. The asymmetric Mannich reaction of those novel imine derivatives with 1,3-dicarbonyl compound is also described, and the novel a-imino imide gave improved chemical yield and stereoselectivity compared with those obtained by the use of the conventional a-imino ester-type substrate.
Catalytic Asymmetric Total Syntheses of Quinine and Quinidine
Raheem, Izzat T.,Goodman, Steven N.,Jacobsen, Eric N.
, p. 706 - 707 (2007/10/03)
The catalytic, asymmetric syntheses of quinine and quinidine were achieved in 16 steps. The recently developed salen(Al)-catalyzed enantioselective Michael addition of methyl cyanoacetate served to set the crucial C4 stereocenter in 92% ee, and a late-stage asymmetric dihydroxylation was used to differentiate the common intermediate and access the two desired diastereomeric products with high selectivity. Copyright