Two-alkyne annulations of transition-metal carbene complexes via in situ generated vinyl carbene complexes

Group 6 Fischer carbene complexes: “chemical multitalents” for multi-component reactions

“…The reaction takes place with a high excess of a terminal alkyne 115 in THF providing only moderate yields of phenols 116 [50] (Scheme 21). This pattern of reactivity has also been encountered in the reaction of molybdenum carbene complex 1a (M = Mo, R 1 = Bu) with an 1,7-enyne (9% yield) [34].…”

Metal-Assisted Cycloaddition Reactions in Organotransition Metal Chemistry

“…The synthetic potential of these multistep multicomponent cyclization reactions has not yet been fully explored, and there are examples of other potentially useful sequences such as the topologies [2+2+1+1], 914 giving bicyclo[3.1.0]lactams from chromium aminocarbene complexes and alkynes, or the inter- 850,868 or intramolecular 915 …”

Synthesis of phenols from metal-carbynes and diynes

“…The H NNR and IR spectra of the 3-methyl-5,6,7,8-tetrahydro-2-1 naphthol and 2,3-dihydro-6-methyl-IH-inden-5-ol are identical to those published. 5 The IH NMR spectra of the other products, all previously unknown, showed the resonances and intensitte. required.…”

“…(1-methoxyethylidene)tungsten, 5 or perhaps by losing a cis-ligand 7 and following a path via i or_. 2b,8…”