Calcium Carbide: Versatile Synthetic Applications, Green Methodology and Sustainability

Abstract

Acetylene is a key building block for organic chemistry and potentially can be involved in a diverse range of synthetic transformations. However, critical analysis of practical considerations showed that application of gaseous acetylene in regular synthetic labs encounters a number of difficulties. Safety limitations due to flammable and explosive nature of gaseous acetylene and requirements for specialized high‐pressure equipment impose serious drawbacks. Typical reaction conditions involve excess of gaseous reactant, which is simply released to the atmosphere at the end of the reaction, thus generating waste and causing contamination. Calcium carbide brings a new green and sustainable wave into powerful alkyne transformations and significantly expands the repertoire of traditional acetylene chemistry. The novel trend of using calcium carbide instead of gaseous acetylene is synthetically beneficial and opens a novel reactivity for the C≡C unit. This review highlights recent advances in carbide chemistry, demonstrates its advantages and prospects in term of green synthetic approach.

Sustainable Hydrogenation of Vinyl Derivatives Using Pd/C Catalysts

“…The construction of closed carbon-neutral cycles [10], including the stages of synthesis, application, utilization, and regeneration of carbon-containing molecules, has a fundamentally important role [11]. We previously showed that the conceptual possibility of constructing closed carbon-neutral cycles is provided by atom-economical addition reactions based on calcium carbide (Scheme 1) [12]. Calcium carbide can be obtained by cyclic technology using lime (calcium carbonate and calcium oxide) and various sources of elemental carbon (regenerated carbon, bioderived carbon, coke, charcoal, anthracite, etc.)…”

“…Calcium carbide can be obtained by cyclic technology using lime (calcium carbonate and calcium oxide) and various sources of elemental carbon (regenerated carbon, bioderived carbon, coke, charcoal, anthracite, etc.) [12,13]. Acetylene, the simplest alkyne, released during hydrolysis is a molecule of choice for a sequence of atom-economic addition reactions.…”

“…constructing closed carbon-neutral cycles is provided by atom-economical addition reactions based on calcium carbide (Scheme 1) [12]. Calcium carbide can be obtained by cyclic technology using lime (calcium carbonate and calcium oxide) and various sources of elemental carbon (regenerated carbon, bioderived carbon, coke, charcoal, anthracite, etc.)…”

3D Printing to Increase the Flexibility of the Chemical Synthesis of Biologically Active Molecules: Design of On-Demand Gas Generation Reactors

“…The approach developed here is based on two key components: the use of on-demand production of gas from a suitable precursor and the design of the reactor using 3D printing. The precursor for acetylene is calcium carbide, powerful potential of which has recently been studied through a series of chemical transformations, where acetylene is formed by the addition of water [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ]. However, the presence of calcium carbide, water, and calcium hydroxide (a side product) is not compatible with a large number of water- or base-sensitive chemical reactions.…”

Cycloaddition Reactions of in situ Generated C2D2 in Dioxane: Efficient Synthetic Approach to D2‐Labeled Nitrogen Heterocycles

“…A method for the in situ generation of a D 2 ‐labeled building block, dideuteroacetylene, from calcium carbide and deuterium oxide has been reported recently [3d–h] . Several procedures for the synthesis of specific classes of deuterated compounds from in situ generated C 2 D 2 have been developed.…”