A new and general method for the synthesis of tripeptide aldehydes based on the multi-component Ugi reaction
作者:Michał Mroczkiewicz、Ryszard Ostaszewski
DOI:10.1016/j.tet.2009.03.018
日期:2009.5
Tripeptide aldehydes, such as Z-Leu-Leu-Leu-H (MG-132), are an important class of compounds due to their biological activity. A new, generalmethod for the synthesis of tripeptide aldehydes based on the multi-component Ugi reaction was developed. A careful choice of isocyanides makes it possible to obtain tripeptide precursors whose functionalization led to target structures. This method can be used
Construction of combinatorial chemical libraries using a rapid and efficient solid phase synthesis based on a multicomponent condensation reaction
作者:Sang Woong Kim、Shawn M. Bauer、Robert W. Armstrong
DOI:10.1016/s0040-4039(98)01547-0
日期:1998.9
A 96 member library of acylated dipeptides based on a known anticonvulsant was synthesized utilizing an Ugi four component condensation followed by derivitization through nucleophilic displacement of a Weinreb type amide. The library afforded compounds in reasonable yield and high purity after cleavage from solid support.
Synthesis of Unsymmetrical 3,4-Diaryl-3-pyrrolin-2-ones Utilizing Pyrrole Weinreb Amides
作者:Jessica G. Greger、Sarah J. P. Yoon-Miller、Nathan R. Bechtold、Scott A. Flewelling、Jacob P. MacDonald、Catherine R. Downey、Eric A. Cohen、Erin T. Pelkey
DOI:10.1021/jo2013516
日期:2011.10.21
A regiocontrolledsynthesis of unsymmetrical 3,4-diaryl-3-pyrrolin-2-ones has been achieved in three steps from 1,2-diaryl-1-nitroethenes with pyrrole-2-carboxamides (pyrrole Weinreb amides) serving as the key linchpin intermediates. Two different methods for the preparation of the requisite nitroalkenes were investigated: (1) modified Henry reaction between arylnitromethanes and arylimines; and (2)
Gold(I)-Catalyzed Asymmetric Aldol Reaction of N-Methoxy-N-methyl-.alpha.-isocyanoacetamide (.alpha.-Isocyano Weinreb Amide). An Efficient Synthesis of Optically Active .beta.-Hydroxy .alpha.-Amino Aldehydes and Ketones
作者:Masaya Sawamura、Yuki Nakayama、Tomoki Kato、Yoshihiko Ito
DOI:10.1021/jo00111a034
日期:1995.3
Asymmetric aldol reaction of N-methoxy-N-methyl-alpha-isocyanoacetamide (alpha-isocyano Weinreb amide) with aldehydes [RCHO: R = Ph, Me, i-Pr, (E)-MeCH=CH, (E)-BnOCH(2)CH=CH] in the presence of a gold(I) catalyst prepared in situ from [Au(c-HexNC)(2)]BF4 and chiral ferrocenylphosphine ligand (R)-N-methyl-N-(2-morpholinoethyl)-1-[(S)-1',2-bis(diphenylphosphino)ferrocenyl]ethylamine gave high yields of optically active trans-5-alkyl-2-oxazoline-4-(N-methoxy-N-methylcarboxamides) with high diastereo- and enantioselectivities. The diastereoselectivities (trans:cis) and enantiomeric excesses of the trans-oxazolines for the reaction with 1 mol % of the catalyst are as follows: R = Ph, 97:3, 96% ee; R = Me, 95:5, 97% ee; R = i-Pr, 98:2, 97% ee; R = (E)-MeCH=CH, 97:3; 99% ee; (E)-BnOCH(2)CH=CH, 96:4, 95% ee. These optically active oxazolines were converted to N,O-protected beta-hydroxy-alpha-amino aldehydes and ketone in high yields. An N-protected alpha-amino aldehyde (R = Ph) lacking the beta-hydroxyl group was also obtained through the catalytic hydrogenolysis of the oxazoline.