Cyclopropylcarbene complexes reactions

The presence of a cyclopropyl moiety in the carbene complexes makes them useful for synthesis. The cyclopropylcarbene complexes 95 undergo a cycloaddition reaction with alkynes to give the cyclopentenones 96 [51]. The reaction course is explained as being metallacyclopentene fragmentation. (Scheme 34)... 

Hypothetical (carbene)gold(i) structures of intermediates and reaction coordinates have been calculated (B3LYP/ 6-31G and LAN2DZ levels) for (H3P)Au+-catalyzed cyclization reactions of terminal enynes. The endocyclic skeletal rearrangement reactions were found to proceed exclusively via cyclopropylcarbene complexes.240... 

Cyclopentenones. Reaction of the cyclopropylcarbene complex 1 with di-phenylacetylene in 1% aqueous dioxane results in the cyclopentenone 2 as the major product. The carbonyl group of 2 is derived from a CO ligand of 1, and C,... 

While the first transition metal carbene complex was reported in 1964134, the first cyclopropylcarbene complex salt [(CO)5Cr=C(chromium hexacarbonyl, followed by tetramethylammonium bromide135. Subsequent reaction with trimethyloxonium fluoro-borate gave methoxycarbene complex (CO)5Cr=C(OMe)(c-Pr) (equation 62)136. 

Ring-opening reactions of cyclopropylcarbene and -carbyne complexes have been used in the synthesis of open-chain products, cyclopentenones, cyclopentadienones, cyclohepta-... 

Alkynyl complexes have been reported to undergo [2+2] and [2+4] cycloaddition reactions with ketenes Alkynes have been reacted with cyclopropylcarbene-chromium... 

The reaction between cyclopropylcarbene-tungsten complexes and alkynes has been studied by Herndon (Eq. 31). Both inter- and... 

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