Analysis of key steps in the catalytic cross-coupling of alkyl electrophiles under Negishi-like conditions.
نویسندگان
چکیده
The use of tpy'(tpy'= 4,4',4''-tri-tert-butyl-terpyridine) as a ligand for nickel allows for the isolation of a Ni(I)-alkyl complex and a Ni(II)-alkyl halide complex, both of which can be used as mechanistic probes of key steps in alkyl cross-coupling reactions.
منابع مشابه
Evidence for a NiI active species in the catalytic cross-coupling of alkyl electrophiles.
Addition of terpyridine to (TMEDA)Ni(CH3)2 results in the high-yield formation of (terpyridyl)NiMe (3). This NiI organometallic complex was found to be capable of transferring its methyl group to iodocyclohexane to produce methylcyclohexane in high yield. Compound 3 can also serve as an initiator for the catalytic cross-coupling of alkyl electrophiles performed under Negishi-like conditions.
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Although nickel-catalyzed stereoconvergent couplings of racemic alkyl electrophiles are emerging as a powerful tool in organic chemistry, to date there have been no systematic mechanistic studies of such processes. Herein, we examine the pathway for enantioselective Negishi arylations of secondary propargylic bromides, and we provide evidence for an unanticipated radical chain pathway wherein o...
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ورودعنوان ژورنال:
- Chemical communications
دوره 33 شماره
صفحات -
تاریخ انتشار 2005