Amino acid functionalisation using the 2-phosphaethynolate anion. A facile route to (phosphanyl)carbonyl-amino acids
E N Faria1, A R Jupp, J M Goicoechea
1Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, OX1 3TA, Oxford, UK. jose.goicoechea@chem.ox.ac.uk.
Abstract:
We describe the reactivity of the 2-phosphaethynolate anion (PCO-) towards enantiomerically pure α-amino acids (AAs) resulting in the formation of novel salts of phosphinecarboxamides bearing chiral functionalities. These transformations occurred quantitatively with all but one of the amino acids trialled (the basic amino acid arginine was found to be unreactive). The resulting ionic species can be readily protonated to afford N-(phosphanyl)carbonyl-amino acids, a novel group of amino acids bearing primary phosphine functionalities.
Related Concept Videos
Amines to Amides: Acylation of Amines
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
Preparation of 1° Amines: Gabriel Synthesis
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Acid Halides to Amides: Aminolysis
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
Preparation of Amides
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...
Preparation of 1° Amines: Azide Synthesis
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Phase II Reactions: Sulfation and Conjugation with α-Amino Acids


