Synthesis of Protected 3,4- and 2,3-Dimercaptophenylalanines as Building Blocks for Fmoc-Peptide Synthesis and Incorporation of the 3,4-Analogue in a Decapeptide Using Solid-Phase Synthesis

Abstract

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The Versatile and Strategic O-Carbamate Directed Metalation Group in the Synthesis of Aromatic Molecules: An Update

“…While alternative syntheses have been reported (e.g., selective carboxylation of 98 to 97 , hydrolysis of ester groups in 104 to form 102 and selective carboxylation of 105 to form 106 ) and developed for large-scale commercial production, − these routes typically involve high temperatures, dangerous materials, and corrosive reagents in variable yields. Therefore, the comparative examination of synthetic reactions in Table competitively positions O -carbamate D o M methodology against other procedures for the manipulation of contiguously functionalized substituted aromatic derivatives.…”

Phosphine Catalyzed Michael-Type Additions: The Synthesis of Glutamic Acid Derivatives from Arylidene-α-amino Esters

“…Considering this last approach, α-substituted glutamates have been mainly obtained via the Michael-type additions of glycine derivatives (glycine templates) onto the corresponding α,β-unsaturated reagents. This reliable strategy employs N -arylidene-α-amino acid esters [ 14 , 15 , 16 ] or tert -butyl N -benzylidieneamino glycinate [ 17 , 18 , 19 , 20 , 21 , 22 ] ( Scheme 1 a) and even activated N -arylideneaminomalonates [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ] ( Scheme 1 b) as starting materials. In all cases, phase transfer catalysis (PTC) conditions or the employment of organic superbases are the most common trends to complete the reaction.…”

Development of a synthetic equivalent of α,α-dicationic acetic acid leading to unnatural amino acid derivatives via tetrafunctionalized methanes

“…The acidic methylene group readily generates enolate, which reacts with up to two electrophiles, and subsequent hydrolysis and decarboxylation lead to the formation of α,α-disubstituted acetic acids (Scheme 1, upper). 1,2 Through this process, diethyl malonate serves as a synthetic equivalent of α,α-dianionic acetic acid (Fig. 1, upper).…”