Potassium‐Zincate‐Catalyzed Benzylic C−H Bond Addition of Diarylmethanes to Styrenes

Abstract

Direct functionalization of the benzylic C À Hb ond of diarylmethanes is an important strategy for the synthesis of diarylmethine-containing compounds.H owever,t he methods developed to date for this purpose require as toichiometric amount (usually more) of either as trong base or an oxidant. Reported here is the first catalytic benzylic C À Hbond addition of diarylmethanes to styrenes and conjugated dienes.A potassium zincate complex, generated from potassium benzyl and zinc amide,acts as acatalyst and displays good activity and chemoselectivity.C onsidering the atom economy of the reaction and the ready availability of the catalyst, this reaction constitutes ap ractical, efficient method for diarylalkane synthesis.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Alkali–Amide-Catalyzed One-Pot Aminoallylation of Aldehydes with Allylbenzenes

“…6 Nucleophiles with relatively acidic C(sp) 3 −H bonds (pK a ≈ 18−25), such as aldehydes, malonic acids, nitroalkanes, and ketones can effectively undergo a deprotonative addition reaction with several electrophiles. 7 Recently, the functionalization of weakly acidic C(sp) 3 −H bonds (pK a > 30), such as esters, nitriles, amides and alkylazaarenes, catalyzed by the Brønsted base has also been developed by Pines,8 Knochel, 9 Guan, 10 Shigeno and Kondo, 11 and Kobayashi. 12,13 More recently, catalytic deprotonation of benzylic C(sp) 3 − H bonds (pK a > 40) of simple toluenes have been reported with Brønsted bases, such as Na or K by Pines,14 n-BuLi/LiK-(OCH 2 CH 2 NMe 2 ) 2 /Mg(OCH 2 CH 2 OEt) 2 by Screttas, 15 TMAF/N(TMS) 3 by Shigeno and Kondo, 16 and t-BuOK and LiTMP or KCH 2 TMS and KN(SiMe 3 ) 2 by Kobayashi.…”