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AHA Erlebnis: CaC(2), used to produce acetylene until several decades ago, is re-emerging as a cheap, sustainable resource synthesized from coal and lignocellulosic biomass. We report efficient catalytic protocols for the synthesis of functional acetylene derivatives from CaC(2) through aldehyde, alkyne, and amine (AAA) as well as alkyne, haloalkane, and amine (AHA) couplings, and in addition demonstrate its use in click and Sonogashira chemistry, showing that calcium carbide is a sustainable and cost-efficient carbon source.

Friendly competition: A three‐component reaction system composed of calcium carbide, an aryl aldehyde, and an amine gave enaminones or propargylamines (see picture) in a predictable manner through competitive pathways. The system enables the cost‐efficient synthesis of a variety of enaminones from readily accessible small molecules and demonstrates the versatility of the acetylide ion, which can be used to bridge electrophiles and nucleophiles.

Propargyl alcohols containing a terminal alkyne group are highly important and versatile intermediates. Here, we report the synthesis of these compounds from an inexpensive and renewable resource, calcium carbide (CaC 2 ). No metal catalysts are required in this new protocol and the reactions take place under very mild conditions. Scheme 1 Propargyl alcohols containing (a) an internal alkyne and (b) a terminal alkyne. † Electronic supplementary information (ESI) available. See