Various 2-amino-4-aryl-3-cyano-4H-chromenes have been quantitatively prepared by dry ball milling in the presence of catalytic Na2CO3. The orientation specificities are discussed; existing misattributions are pointed out and clarified by NMR.

A truly green, solventless, and fast protocol for the quantitative preparation of biologically active xanthene derivatives with 10 mol% sulfonated graphitic carbon nitride (Sg─CN) as a heterogeneous acidic catalyst was developed. Excellent yields, low cost, solvent-free conditions, high catalytic activity, reusability of the catalyst, simple workup, and heterogeneous carbon-based catalyst make the present method particularly attractive from a green chemistry perspective.

Synthesis of Various 2-Amino-4-aryl--3-cyano-4H-chromenes Without Heating. -The environmentally benign reaction proceeds regioselectively with quantitative product yields and does not require organic solvents. -(QAREAGHAJ, O. H.; MASHKOURI, S.; NAIMI-JAMAL*, M. R.; KAUPP, G.; RSC Adv. 4 (2014) 89, 48191-48201, http://dx.

Preparation of many kinds of N-, O-, and S-heterocycles from aryl/alkyl alkynyl aldehydes were investigated in recent years. In this review, the synthesis of bioactive heterocycles using by substituted alkynyl aldehydes is highlighted.

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