Carboxylic acids, conjugated from alkynes

Alkynes from halides also alkynes from alkynes Esters from alcohols also esters from carboxylic acids Alkyls from alkenes (Conjugate Reduction)... 

The stoichiometric head-to-head oxidative coupling of alkynes with CpRuBr(COD) affords a metallacyclic biscarbene complex [22], This process has been used to initiate catalytic formation of the RCH=CH-CH=C(Y)R backbone, to produce Junctional dienes from alkynes by addition of H-Y. The complex [Cp RuCl(COD)[ successfully catalyzes this new chemical transformation, involving the combination of two molecules of alkynes and one molecule of carboxylic acid to afford functional conjugated dienes (Scheme 4) [23]. 

Hydrocarhoxylation and chlorocarboxylation. Pd/C catalyzes the formation of carboxylic acids from conjugated dienes and alkynes. The reaction system also contains CO, HCOOH (or oxalic acid), PhsP, and l,4-bis(diphenylphosphino)butane. For chlorocarboxylation, anhydrous HCl is used as a coreagent. ... 

Haloalkanes also react with carbon nucleophiles. These reactions increase the length of the carbon chain. One example of a carbon-containing nucleophile is cyanide ion (CN), which reacts with haloalkanes to give nitriles with the formula R—CN. We will see later that nitriles can be transformed into carboxylic acids and amines. Carbon-containing nucleophiles derived from aUtynes are called alkynide ions. These nucleophiles, the conjugate bases of alkynes, react to form alkynes containing the carbon atoms of both the haloalkane and the alkynide. 

---