Carbonylative Sonogashira Reactions

Beller and X.-F. Wu, Transition Metal Catalyzed Carbonylation Reactions, DOI 10.1007/978-3-642-39016-6 5, Springer-Verlag Berlin Heidelberg 2013 

2-methyl-3-butyn-2-ol under biphasic conditions to furanones were also described 

The use of phosphites, e.g., P(OPh)3 as a ligand in palladium-catalyzed carbonylative Sonogashira coupling, was first reported by Trzeciak and colleagues 

Kondo and lizuka presented a palladium-catalyzed CO-free method for alky-none synthesis, which applies stoichiometric amounts of Mo(CO)6 as a CO source 

Later on, the same group presented an unusual variation of the palladium-catalyzed carbonylative Sonogashira coupling reaction [46]. Here, a magnetically 

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In 2008, Bhanage and coworkers [50a] reported on a copper-catalyzed carbonylative Sonogashira reaction of aryl iodides. In this procedure, copper bis(2,2,6,6-tetramethyl-3,5-heptanedionate) [Cu(TMHD)2 was used as the catalyst for this transformation and NEtj as base. Alkynones were produced in good yields. Recently, Xia and coworkers [50b] described a general and efficient copper-catalyzed... 

Water as a green solvent has been successfully applied as a reaction medium for palladium-catalyzed carbonylative Sonogashira reactions (Scheme 5.11) [36]. Instead of using alkynes, activated acetylenes stibanes can also be applied as coupling partners in carbonylations. An example is the palladium-catalyzed carbonylative Sonogashira coupling of alkynyl stibanes with aryl iodides that was published by Kakusawa and Kurita in 2006 [37], The reaction was carried out under 1 bar of CO in DMAc using 5 mol% of Pd(OAc)2 and 20 mol% of PPhs. 

The use of ionic liquids and flow chemistry technologies attract increasing attention. Consequently, these novel tools have also been successfully used in carbonylative Sonogashira reactions by Ryu and colleagues [38, 39]. Various al-kynones were synthesized in moderate to good yields at a low pressure of CO in n-butyl methyl imidazolium hexafluorophosphate. The microreactor-based flow system was compared with typical batch conditions, and higher yields could be achieved with flow system (Scheme 5.13). 

Scheme 5.13 Pd-catalyzed carbonylative Sonogashira reaction in ionic liquids...

Scheme 5.17 Pd/C-catalyzed carbonylative Sonogashira reaction of aryl iodides...

Taking the advantages of anilines, Beller and his colleagues developed the first general and efficient methodology for carbonylative Sonogashira reaction of anilines [51]. This transformation proceeded under mild reaction conditions, and no base was needed. Both aromatic and aliphatic alkynes are suitable starting materials, and 30 different kinds of alkynones were produced in moderate to excellent yields (Scheme 5.22). 

Elegant synthetic applications of carbonylative Sonogashira reactions were described by Muller and his group. For example, in 2005 they succeeded in producing palladium-catalyzed one-pot, four-component carbonylations for the... 

In this chapter, we have discussed the carbonylative Sonogashira reaction of organohalides and their synthetic applications. Palladium-catalysts are still the main catalysts in this area. From the mechanism point of view, the same as the... 

Scheme 5.33 Copper-catalyzed carbonylative Sonogashira reaction...

Carbon monoxide can serve as building block for many palladium-catalyzed reactions e.g., in carbonylative Stille reaction, see 4.3, or carbonylative Sonogashira reaction ). 

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