1,4-butynediol formation

AIPO4 could be an adequate support component to enable a tailored Ni-Cu catalyst to obtain the most appropriate activity and selectivity in the semihydrogenation of 1,4-butynediol, not only due to its high degree of selectivity toward the olefinic compound, but also because there was no formation of other side reaction products, as described (refs. 2 and 11) in the literature. 

The main product of 1,4-butynediol hydrogenation for this reaction is cis-butenediol. Simultaneously, the parallel reaction of 1,4-butenediol hydrogenation as well as cis-trans transformation takes place at the second stage. For this process, cis-1,4-butenediol formation is most interesting from a practical point of view. Processes... 

The Reppe process is a method that was developed in the 1940s and typical manufacturers include BASF, Ashland, and Invista. Cu-Bi catalyst supported on silica is used to prepare the 1,4-butynediol by reacting formaldehyde and acetylene at 0.5 MPa and 90-110 C (Eq. (10.2)). The copper used in the reaction is converted to copper(I) acetylide, and the copper complex reacts with the additional acetylene to form the active catalyst. The role of bismuth is to inhibit the formation of water-soluble acetylene polymers (i.e., cuprenes) from the oligomeric acetylene complexes on the catalyst [5a]. The hydrogenation of 1,4-butynediol is accom-pUshed through the use of Raney Ni catalyst to produce 1,4-butanediol (Eq. (10.3)). The total yield of 1,4-butanediol production is 91% from acetylene [5b]. Since acetylene is a highly explosive compound, careful process control is necessary. 

Compound 64 is a true nickel(O) alkyne complex with no agostic interactions between Ni and the methyl groups of the ligands. In the crystal the molecules are associated by four intermolecular hydrogen-bond interactions between neighboring butynediol ligands. This leads to the formation of chain polymers. 

In 2006, Gagosz reported the gold-mediated stereoselective synthesis of 2,5-dihydrofurans from butynediol monobenzoates at room temperature. The transformation involved two sequential gold-catalysed reactions the formation of an allene derivative followed by a cyclisation. The reaction was... 

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