Diastereoselective synthesis of 3-amino-2-hydroxyalkanoic acid derivatives
摘要:
Both diastereomers of 3-amino-2-hydroxyalkanoic acid derivatives were synthesized selectively by LDA-induced reaction of N-methoxycarbonyl-1-methoxyamines with O-protected N,N-dimethylglycolamides. The inversion of the diastereoselectivity was highly achieved by 1) selecting the O-protecting groups and 2) the addition of Ti(OPr-i)(4).
Synthesis of Methyl-1-(<i>tert</i>-butoxycarbonylamino)-2-vinylcyclopropanecarboxylate via a Hofmann Rearrangement Utilizing Trichloroisocyanuric Acid as an Oxidant
作者:Zackary D. Crane、Paul J. Nichols、Tarek Sammakia、Peter J. Stengel
DOI:10.1021/jo101504e
日期:2011.1.7
A trichloroisocyanuric acid (TCCA) mediated Hofmann rearrangement was utilized to synthesize methyl-1-(tert-butoxycarbonylamino)-2-vinylcyclopropanecarboxylate. A variety of functional groups are tolerated in this reaction including vinyl, cyclopropyl, pyridyl, aryl, benzyl, and nitro groups.
This report describes a new method to prepare opticallyactive β-hydroxyamines starting from primary amines. The method consists of a transformation of N-methoxycarbonylated primary amines to the corresponding enecarbamates utilizing electrochemical oxidation and an asymmetric hydroboration of the enecarbamates to produce opticallyactive β-hydroxyamines.
Preparation of Acyclic<i>N</i>-Acyl-<i>N</i>,<i>O</i>-acetals by Decarboxylation of<i>N</i>-Protected α-Amino Acids and Studies of Asymmetric Amidoalkylation with Trimethylsilyl Cyanide
作者:Kenn E. Harding、Lee T. Liu、David G. Farrar、M. Todd Coleman、Susan K. Tansey
DOI:10.1080/00397919108021290
日期:1991.6
Abstract Oxidative decarboxylation of N-acyl-α-amino acids with lead tetra-acetate followed by treatment with methanol provides a facile method for preparation of acyclic N-acyl-N,O-acetals, which can be used in asymmetric α-amidoalkylation reactions using trimethylsilyl cyanide as nucleophile.
The reaction of N-acyl-alpha-methoxyamines with allyl-, propargyl-, and benzylzinc bromides and Reformatsky reagents proceeds in THF at room temperature. Homoallyl- and homopropargylamines and beta-amino esters are synthesized in good yields.
A New Method for the Synthesis of β-Amino Acid Derivatives and β-Lactams. Reaction of <i>N</i>-Alkoxycarbonyl-1-methoxyamines with Esters
作者:Naoki Kise、Nasuo Ueda
DOI:10.1021/jo990821q
日期:1999.10.1
The reaction of N-alkoxycarbonyl-1-methoxyamines with esters is an alternative to the reaction of imines with esters for the synthesis of beta-amino acid derivatives. In this reaction, N-alkoxycarbony-1-methoxyamines corresponding to unstable imines can also be employed. Although anti adducts were obtained preferentially in the absence of Ti complexes, the diastereoselectivity of this reaction was reversed by the addition of Ti(OPr-i)(4). The obtained adducts were transformed to the corresponding beta-lactams.