734548-35-7Relevant articles and documents
Enantio- and diastereoselective, stereospecific Mannich-type reactions in water
Hamada, Tomoaki,Manabe, Kei,Kobayashi, Shu
, p. 7768 - 7769 (2007/10/03)
Catalytic asymmetric Mannich-type reactions in water proceeded in high yields and selectivities using a combination of ZnF2 and a chiral diamine that has the methoxy groups on the aromatic rings. In these reactions, either syn- or anti-Mannich
Catalytic, asymmetric Mannich-type reactions of N-acylimino esters: Reactivity, diastereo- and enantioselectivity, and application to synthesis of N-acylated amino acid derivatives
Kobayashi, Shu,Matsubara, Ryosuke,Nakamura, Yoshitaka,Kitagawa, Hidetoshi,Sugiura, Masaharu
, p. 2507 - 2515 (2007/10/03)
In the presence of a catalytic amount of Cu(OTf)2-chiral diamine 3e complex, N-acylimino esters reacted with silyl enol ethers to afford the corresponding Mannich-type adducts in high yields with high enantioselectivities. A wide variety of silyl enol ethers derived from ketones, as well as esters and thioesters, reacted smoothly. In the reactions of α-substituted silyl enol ethers (α-methyl or benzyloxy), the desired syn-adducts were obtained in high yields with high diastereo- and enantioselectivities. Several intermediates for the synthesis of biologically important compounds were prepared using this novel catalytic asymmetric Mannich-type reaction, and at the same time, absolute and relative stereochemical assignments were made. In addition, it has been revealed that alkyl vinyl ethers reacted with N-acylimino esters in the presence of a catalytic amount of the Cu(II) catalyst to give the corresponding Mannich-type adducts in high yields with high enantioselectivities. This is the first example of catalytic asymmetric Mannich-type reactions with alkyl vinyl ethers. The reaction mechanism, structure of chiral catalyst-electrophile complexes, and transition states of these catalytic asymmetric reactions were assumed based on X-ray crystallographic analysis of the Cu(II)-chiral amine complex, PM3 calculations, and FT-IR analyses, etc. Finally, (1R,3R)-N-(3-hydroxy- 1-hydroxymethyl-3-phenylpropyl)dodecanamide (HPA-12, 1), a new inhibitor of ceramide trafficking from endoplasmic reticulum to the site of sphingomyerin (SM) synthesis, has been synthesized efficiently using the present Mannich-type reaction as a key step. The synthesis involved three steps (two-pot), and total yield was 82.9%.
A large-scale preparation of (3S,4S)-3-(tert-butoxycarbonyl)amino-4-methylpyrrolidine and its analogs from L-aspartic acid
Yoshida, Toshihiko,Takeshita, Makoto,Orita, Hitomi,Kado, Noriyuki,Yasuda, Shingo,Kato, Hideo,Itoh, Yasuo
, p. 1128 - 1131 (2007/10/03)
(3S,4S)-3-(tert-Butoxycarbonyl)amino-4-methylpyrrolidine (12a) was synthesized from L-aspartic acid (4) on a large scale. Methylation of dimethyl (2S)-N-benzyl-N-(9-phenylfluoren-9-yl)aspartate (5), easily derived from 4, with methyl iodide gave (3R)-3-methylaspartate (6a) in 91% yield with high diastereoselectivity. Reduction of 6a with lithium aluminum hydride, followed by hydrogenolysis, protection with di-tert-butyl dicarbonate, and mesylation gave 10a in 89% overall yield. Subsequently, reaction of 10a with benzylamine under a nitrogen atmosphere at room temperature, followed by hydrogenolysis, gave the target compound (12a) in 65% overall yield. In a similar manner to that described for the preparation of 12a from 5, compound 5 was converted into 4-ethyl and 4-propyl derivatives (12b,c) in 34% and 38% overall yields.
