Metal-free and benign approach for the synthesis of dihydro-5′H-spiro[benzo[c]chromene-8,4′-oxazole]-5′,6(7H)-dione scaffolds as masked amino acids.

Autor:	Shafiee, Behnaz, Duffield, Joseph, Timm, Rudy, Liyanage, Rohana, Lay, Jackson O., Khosropour, Ahmad R., Amiri Rudbari, Hadi, Beyzavi, M. Hassan
Předmět:	AMINO acid derivatives AMINO acids DECARBOXYLATION CONDENSATION PROPYLENE carbonate
Zdroj:	Green Chemistry; 5/21/2019, Vol. 21 Issue 10, p2656-2661, 6p
Abstrakt:	An eco-friendly, straightforward, and three-component condensation/cascade reaction of 4-hydroxycoumarins and (Z)-azlactones to construct diversified dihydro-5′H-spiro[benzo[c]chromene-8,4′-oxazole]-5′,6(7H)-diones as new masked amino acid derivatives has been developed with high to excellent yields and regio- and diastereoselectivity. This metal-free reaction proceeds via a one-pot cascade Michael addition/lactonization/decarboxylation reaction utilizing reusable propylene carbonate as a green solvent. The scale-up examination was also performed, showing high atom economy under the reaction conditions. Moreover, the mechanism of the reaction was further investigated using isotope-labeling, LC-MS monitoring, and TLC-MALDI-MS. [ABSTRACT FROM AUTHOR]
Databáze:	Complementary Index
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