Dimethylamine, tungsten complex

Alkylation of sp3 C-H bonds adjacent to a heteroatom such as nitrogen and oxygen is possible. The early works using tungsten or iridium complexes involved the reaction of dimethylamine with 1-pentene (Equation (29)) and the alkylation of a C-H bond adjacent to oxygen with / r/-butylethylene.34,34a,34b... 

Acylmetallates lp,q generated by addition of lithio prop-2-ynylic ethers to hexacarbonyl chromium or tungsten afford oxacyclopenten-2-ylidene complexes 173 on contact with wet silica gel (Scheme 73).194 The chromium complex 173 (M = Cr) undergoes a condensation with tolane to give a 1,4-dioxy aromatic compound 174. Addition of cyclopentadiene to 173 (M = W) affords a Diels-Alder adduct 176 in a 1 3 exo/endo ratio,195 while addition of dimethylamine quite unexpectedly does not lead to production of an aminocarbene complex but to formation of 5,5 -diphenyl-2,2 -bifuran 175 (Scheme 73).196... 

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