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20.2.1.6.5.1 Variation 1: Hydrometalation–Carboxylation Sequence

DOI: 10.1055/sos-SD-020-00172

Evano, G.Science of Synthesis, (200720231.

Transition-metal catalysts provide powerful tools for 1,2-addition reactions to unactivated C=C bonds, such as hydrometalation. This enables the synthesis of carboxylic acids from alkenes by trapping the newly formed organometallic reagent with carbon dioxide. Finkbeiner and Cooper reported in the early 1960s that a mixture of propylmagnesium bromide and titanium(IV) chloride was an efficient catalyst for the hydromagnesiation of alkenes, placing the magnesium at the terminal position of the alkene, except when a benzylic Grignard can be formed. By reacting the obtained Grignard reagent with carbon dioxide, the carboxylic acids 6467 were obtained (Scheme 24).[‌136‌,‌137‌]

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