| 研究実績の概要 |
Iron-catalyzed C-H bond activation is of much interest because economic and environmental merits of iron, but the reactivity of catalytic organoiron species is difficult to control, hampering the development of efficient and selective reactions. We have developed the reaction of pivaloylamides with organozinc reagents in FY2014, but poor control of the reactivity of organoiron species resulted in very narrow reaction scope and little practicality.
In order to solve these problems, in FY 2015 we have developed a new catalytic system based on organoiron(III) species. Thus, we discovered that the use of a bidentate directing group, a diphosphine ligand and a mild organometallic reagent enables an organoiron(III)-catalyzed C-H bond activation reaction that shows broad scope and versatility. The iron(III) catalytic system was used for the follwing two reactions.
1) Oxidative reaction of (hetero)arene and alkeneamides with aryl-, alkenyl-, and alkyl boronates. This reaction is the first example of stereospecific diene and triene synthesis via C-H bond activation, and demonstrates the versatility of the organoiron(III) catalyst.
2) Iron-catalyzed alkylation of (hetero)arene and alkeneamides with primary and secondary alkyl tosylates and halides. This reaction is the first example of efficient C-H alkylation with alcohol derivatives.
With the new iron(III) catalytic system in hand, we are now pursuing the development of efficient C(sp3) activation reactions, and preliminary results show that a pivaloylamide can be efficiently arylated and alkenylated with organoborate reagents.
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