Catalytic Direct‐Type Addition Reactions of Alkylarenes with Imines and Alkenes

Abstract

Catalytic addition reactions of very weakly acidic nonactivated alkylarenes such as toluene and its derivatives were developed by using a strongly basic mixed catalyst system under mild reaction conditions. The addition reactions with imines and alkenes proceeded smoothly under proton‐transfer conditions to afford the desired products in good to high yields, and high levels of regio‐ and stereoselectivity were achieved. It was also revealed that the asymmetric addition reaction of an alkylarene was possible.

Rhodium‐Catalyzed Stereoselective Deuteration of Benzylic C–H Bonds via Reversible η6‐Coordination

“…One obstacle to the development of such methods derives from the small difference in electronegativity between carbon and hydrogen atoms, which makes heterolytic fission of nonpolar C(sp 3 )−H bonds a formidable challenge. Specifically, deprotonation of unbiased benzylic C−H bonds (p K a >40 in DMSO, [11] Scheme 1c) requires a strong base [12] such as n BuLi, [12a] NaHMDS (sodium hexamethyldisilazide), [12b] or KOtBu/LiTMP (lithium tetramethylpiperidide) [12c] . Meanwhile, compared with the C−H bonds of methyl groups, secondary and tertiary C−H bonds are more resistant to deprotonation owing both to the electron‐donating effect of the alkyl groups and to steric hindrance.…”