Dehydrooligopeptides. V. Synthesis of N-carboxy .ALPHA.-dehydroamino acid anhydrides and their transformation to .ALPHA.-dehydroamino acid and dehydrooligopeptide derivatives.
The synthesis of N-carboxy α-dehydroamino acid anhydrides (ΔNCA) from benzyloxycarbonyl-α-dehydroamino acids and the subsequent conversion of these products into new α-dehydroamino acid and dehydrooligopeptide derivatives are described. It was found that the new ΔNCA derivatives were very useful synthons for dehydropeptides. The racemization behavior and configurational determination of all the new dehydrooligopeptides thus obtained are discussed.
An enantioselective one‐pot Michael/Michael/Henry/hemiacetalization reactionbetween α,β‐unsaturated aldehydes, α‐ketoamides, and nitroalkenes under mild conditions catalyzed by a diarylprolinol silyl ether has been developed. The sequential methodology provides a direct approach to a wide range of fully substituted chiral oxabicyclo[2.2.2]octanes with seven contiguous stereocenters in moderate to
已经开发了在二芳基脯氨醇甲硅烷基醚催化的温和条件下,α,β-不饱和醛,α-酮酰胺和硝基烯烃之间的对映选择性单锅Michael / Michael / Henry /半缩醛化反应。顺序方法学提供了一种直接方法,可处理多种具有七个连续立体中心的全取代手性氧杂双环[2.2.2]辛烷,中度至优异的收率(高达99%),高至极好的非对映选择性(高达> 25:1 dr)以及高到极好的对映选择性(高达99%ee)。
Mild one-pot conversion of carboxylic acids to amides or esters with Ph3P/trichloroisocyanuric acid
作者:Rogério da C. Rodrigues、Igor M.A. Barros、Edson L.S. Lima
DOI:10.1016/j.tetlet.2005.06.127
日期:2005.8
The reaction of trichloroisocyanuric acid (TCICA) and triphenylphosphine in the presence of a carboxylic acid results in the in situ formation of the corresponding acid chloride under mild conditions. Subsequent addition of amines or alcohols, in the presence of a tertiary amine affords the corresponding amides, or esters, in good to excellent yields. The methodology was applied to the synthesis of
The present invention discloses compounds of Formula (I), and pharmaceutically acceptable salts, thereof:
which inhibit coronavirus replication activity. The invention further relates to pharmaceutical compositions comprising a compound of Formula (I) or a pharmaceutically acceptable slat thereof, and methods of treating or preventing a coronavirus infection in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a compound of Formula (I) or a pharmaceutically acceptable salt thereof.