Copper-catalyzed carbonylative coupling

Copper-catalyzed carbonylative coupling of ( )-a-(ethylsdanyl)-vinyl zircono-cene chloride derivatives with alkynyliodonium tosylates has been reported to be a mild method for the preparation of vinyl alkynyl ketones in good yields (Scheme 12.30) [39]. 

The construction of -silyl divinyl ketones in many different structural settings has been weU developed. The four principal connections outlined in Scheme 16 are as follows path a, vinyl organome-tallic addition to 3-trimeAylsilyl-2-propenal path b, 3-trialkylsilylvinyl organometallic" addition to enals path c, palladium-catalyzed carbonylation/coupling of 2-trimethylsilylvinyltrimethylstan-nane and path d, acylation of a B-silyl copper reagent. 

Use of IL in other reaction 1-Alkyl-3-methylimidazolium cation-based ILs were used for A-teri-butyloxycarbonylation of amines with excellent chemose-lectivity [32]. 1,3-dialkylimidazolitrm ILs such as [bmim][PFg]. [bmTr][PFg] and [bmTr][NTf2] were reported for reaction media for the Baylis-Hillman reaction [33]. 1-butyl-3-methylimidazohrrm-based IL [bmim][NTf2] is used as solvent for a-methylenations of carbonyl compotmds [34]. M. L. Kantam et al. described copper-catalyzed cross-coupling reaction of arylboronic acids with sulfonic acid for alkylaryl and diaryl sulfones using IL [35]. 

The results show that a number of ruthenium carbonyl complexes are effective for the catalytic carbonylation of secondary cyclic amines at mild conditions. Exclusive formation of N-formylamines occurs, and no isocyanates or coupling products such as ureas or oxamides have been detected. Noncyclic secondary and primary amines and pyridine (a tertiary amine) are not effectively carbonylated. There appears to be a general increase in the reactivity of the amines with increasing basicity (20) pyrrolidine (pKa at 25°C = 11.27 > piperidine (11.12) > hexa-methyleneimine (11.07) > morpholine (8.39). Brackman (13) has stressed the importance of high basicity and the stereochemistry of the amines showing high reactivity in copper-catalyzed systems. The latter factor manifests itself in the reluctance of the amines to occupy more than two coordination sites on the cupric ion. In some of the hydridocar-bonyl systems, low activity must also result in part from the low catalyst solubility (Table I). 

Alkynyl(phenyl)iodonium salts can be effectively used in palladium(O) or copper(I) catalyzed coupling or carbonylative coupling reactions with various organozirconium complexes (Scheme 57) [117-119]. 

Li Y, Ye Z, Bellman TM, Chi T, Dai M (2015) Efficient synthesis of p-CF3/SCF3-substituted carbonyls via copper-catalyzed electrophilic ring-opening cross-coupling of cyclopropanols. Org Lett 17 2186-2189. doi 10.1021/acs.orglett.5b00782... 

SCHEME 7. 26 Copper-catalyzed oxidative cross-dehydrogenative-coupling of 3-ketoesters or 2-carbonyl-substituted phenols with ethers. 

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