Alkylpotassium-Catalyzed Benzylic C–H Alkylation of Alkylarenes with Alkenes

Abstract

Catalytic benzylic C–H alkylation reactions of alkylarenes with alkenes such as β-substituted styrenes and vinylsilanes have been achieved by utilizing alkylpotassium as a catalyst. Various substituted toluene derivatives can be alkylated under mild reaction conditions to afford the desired functionalized hydrocarbons in moderate to high yields.

Base-catalyzed C-alkylation of potassium enolates with styrenes via a metal–ene reaction: a mechanistic study

“…Notably, our mechanistic picture explains the experimental observations in other (ketone and alkylpyridine) CAKES, hence gathering all these reaction classes under the umbrella of a general reaction mechanism. We hope that this study might shed light on related reactivity 31,52…”

“…Hartwig et al highlighted the importance of conducting separate reactions in parallel to draw valid conclusions about KIEs. 30 Intramolecular 31 or intermolecular 32 competition experiments can present 'false positive' results that cannot conclusively identify the RDS (or turnover-limiting step). 33 Therefore, to further investigate the role of deprotonation in amide CAKES, NMP and NMP-d 9 were compared in parallel under conditions demonstrated affording incomplete conversion (10 min at 0°C gave a 40% yield of 20a) and were quenched after an identical time (Fig.…”

“…Nonetheless, a strong argument can be made for rate acceleration via pathway B due to the observed KIE. It is possible that other rate-enhancing additives (LiCl/PMDTA) 31,42 used in these types of reactions function via a similar mechanism.…”

Recent Progress in Benzylic C(sp3)—H Functionalization of Toluene and Its Derivatives

“…该催化过程的关键步骤是形成二烷基酰胺或弱稳定的 碳负离子, 可作为强碱性反应中间体. 随后该课题组还 专门对甲苯与苯基取代的烯烃加成反应做了研究报道 [21] . 吲哚是天然产物和药物中最广泛的骨架之一, 也是 药物化学中必不可少的化合物, 对其的研究也是数不胜 数.…”

Chiral Metal Salts as Ligands for Catalytic Asymmetric Mannich Reactions with Simple Amides

“…Recently, we have focused on developing strong Brønsted base catalyzed addition reactions with weakly acidic carbon pronucleophiles by designing strongly basic reaction intermediates. , Addition reactions of weakly acidic carbonyl and related compounds, such as esters, amides, and alkylnitriles (p K a = 30–35 in DMSO), and their asymmetric variants have been developed. − However, catalytic asymmetric Mannich reactions with weakly acidic simple amides such as propionamides have not yet been achieved. We report here our efforts to realize these reactions using a newly discovered chiral strong Brønsted base catalyst system.…”