The first successful resolution of rac-α-aminoacetals via diastereoisomeric salt formation with optically pure N-protected aminoacids is reported. The absolute configuration assignment of α-aminoacetal enantiomers is performed by an entirely non-racemizing chemical correlation method involving N-protection and a new efficient hydrolysis step followed by a reduction of the resulting N-protected α-aminoaldehyde
作者:Giovanni Muncipinto、Philip N. Moquist、Stuart L. Schreiber、Scott E. Schaus
DOI:10.1002/anie.201103271
日期:2011.8.22
Multicomponent Petasisreactions: The first diastereoselectivePetasisreaction catalyzed by chiral biphenols that enables the synthesis of syn and anti β‐amino alcohols in pure form has been developed. The reaction exploits a multicomponent approach that involves boronates, α‐hydroxy aldehydes, and amines (see scheme).
Process of racemisation of optically active alpha aminoacetals
申请人:Clariant Specialty Fine Chemicals (France)
公开号:US08350092B2
公开(公告)日:2013-01-08
The invention relates to a process for preparing α-aminoacetals substantially in racemic form, comprising a step of oxidizing optically enriched α-aminoacetals to the corresponding oximes, in the presence of a catalyst, and a step of reducing the oximes thus obtained.
On the inhibition of HIV-1 protease by hydrazino-ureas displaying the N→CO interaction
作者:Michael Waibel、Delphine Pitrat、Jens Hasserodt
DOI:10.1016/j.bmc.2009.03.059
日期:2009.5
To create novel HIV-1 protease (HIV PR) inhibitors, we have extended our investigations of the N -> C=O interaction as a moiety that reproduces electrostatic properties of the transition state of peptidolysis. Consequently, we prepared a series of compounds with an unusual hydrazino-urea core. In polar protic media, these adopt solely a cyclic constitution displaying the interaction on one side of the molecule while offering a urea moiety on the opposite side meant to hydrogen-bond with the enzyme flaps. Each inhibitor candidate was obtained via a key series of three synthetic steps employing carbonyl-di-imidazole (CDI). It was thus possible to efficiently fuse two independent building blocks, a hydrazine and a protected aminoaldehyde in a convergent manner. NMR and UV analysis proved that all compounds, when dissolved in polar protic media, existed exclusively in the cyclic constitution exhibiting the N -> C=O interaction. In total, five inhibitor candidates were tested with HIV PR for their potency. The one carrying the least bulk in peripheral substituents showed the highest activity. Its very low molecular weight ( 365 g/mol) holds great promise for future improvements in affinity without violating Lipinski's rule of remaining within the limit of 500 g/mol. (C) 2009 Elsevier Ltd. All rights reserved.
PROCESS OF RACEMISATION OF OPTICALLY ACTIVE ALPHA AMINOACETALS