Cp2TiCl2-catalyzed hydrocarboxylation of alkynes with CO2: formation of α,β-unsaturated carboxylic acids
نویسندگان
چکیده
a,b-Unsaturated carboxylic acids are important chemicals, and can be used as basic materials in the production of plastics, superabsorbent, polymers, and rubbers. Various synthetic methodologies for their synthesis have been developed, for example, oxidation of propene over heterogeneous catalysts at high temperature yielded the a,b-unsaturated carboxylic acids and hydrocarboxylation of alkynes utilization of metal carbonyls complexes also formed the a,b-unsaturated carboxylic acids. From the viewpoint of sustainable chemistry, the development of efficient routes with high atom and stepeconomy under mild conditions could be highly desirable. Carbon dioxide (CO2) is an environmental friendly, low-toxic and abundant carbon source. Many reaction have been developed utilization of CO2 as a C1 feedstock in organic synthesis. The addition of CO2 to alkynes could serve as a most powerful synthetic route for construction of the a,b-unsaturated carboxylic acids. Recently, Ma and co-workers reported a nickelcatalyzed hydrocarboxylation of alkynes with diethyl zinc and CO2 to form the a,b-unsaturated carboxylic acids. In the meantime, Tsuji and co-workers developed a copper-catalyzed hydrocarboxylation of alkynes with CO2 by using hydrosilane as hydrogen source to afford the a,b-unsaturated carboxylic acids. On the other hand, direct reaction of vinylmagnesium halides with CO2 could also afford the a,b-unsaturated carboxylic acids, however, the vinylmagnesium reagents are required preparation in advanced and thus limitation their use. It was reported that alkynes reacted with isobutylmagnesium bromide (BuMgBr) in the presence of a catalytic amount of Cp2TiCl2 to
منابع مشابه
Copper-catalyzed annulation of heteroaromatic β-halo-α,β-unsaturated carboxylic acids with alkynes for the synthesis of indolo[2,3-c]pyrane-1-ones and thieno[2,3-c]pyrane-7-ones.
The annulation of heteroaromatic β-halo-α,β-unsaturated carboxylic acids with alkynes proceeds efficiently in the presence of Cu(OAc)2·H2O as a catalyst to afford the corresponding indolo[2,3-c]pyrane-1-ones and thieno[2,3-c]pyrane-7-ones in moderate to good yields. This strategy offers a simple and efficient route for the synthesis of indolo[2,3-c]pyrane-1-ones and thieno[2,3-c]pyrane-7-ones w...
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