Fisher chromium carbene complex

Sugar acetylene reacted with a Fisher chromium carbene complex to give a phenol derivative, a possible intermediate for naturally occurring aryl-C-glycoside antibiotics (O Scheme 34) [55]. 

Harrity and co-workers described the application of 2-substituted 1-alkynylboronic esters in the Dotz cycloaddition of Fisher chromium carbene complexes, affording in a highly regioselective fashion a novel class of hydroxy-naphthyl boron pinacolates (entry 18, Table 1.3) [217]. These reaction products also provided, upon treatment with ceric ammonium nitrate, the corresponding quinone boronic esters. 

While Fischer carbene omiplexes tend not to react widi unactivated alkenes, many chromium and molybdenum Fisher carbene complexes do mtmocydoprtqianate 1,3-dienes in good yield with high levels of chemo-, regio-, and stereoselectivity... 

Another synthetic pathway to seven-membered rings is by reacting chromium Fisher carbene complexes with... 

The imine bond in 2-imidazolines reacts with Fisher carbenes under irradiation (Scheme 144). Low yields were obtained with monosubstituted imidazolines 608a-c due to thermal decomposition of the substrates under the reaction conditions. Optically active 4,4-disubstituted A -imidazolines 608d-e form azapenams (609d, 610e, 611) with (methoxymethylcarbene)chromium complex in good yields and high diastereoselectivity. The electronic nature of RVR clearly influences the sense of diastereoselectivity (609 vs. 610, 611) <1977JOC3586>. 

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See also in sourсe #XX -- [ ]

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