Stable and Reusable Palladium Nanoparticles‐Catalyzed Conjugate Addition of Aryl Iodides to Enones: Route to Reductive Heck Products

Abstract

An efficient, binaphthyl-backbone-stabilized palladium nanoparticles (Pd-BNP) catalyst for the 1,4-addition of aryl halides to enones has been developed. Thes cope of the reactionh as been studied with various substituted and sterically hindered aryl halides and enones to affordt he conjugate addition productsing oodt oe xcellent yields.T he catalyst has been recovered and reused up to five times without anya ppreciable change in particles ize or reactivity.Scheme 3. Substrate scope of chalcones. Reaction conditions: 1a (0.5 mmol), 2a (0.5 mmol except 3bb where 1mmol was used), Pd-BNP (0.005 mmol), DIPEA(2equiv.) and THF (1 mL) at 80 8 8C; isolatedyields. 1 HNMR (400 MHz, CDCl 3 ): d = 3.63-3.78 (m, 2H), 4.81 (t, J = 7.6 Hz, 1H), 6.90-6.99 (m, 2H), 7.14-7.32 (m, 7H), 7.38-7.48 (m, 2H), 7.48-7.60 (m, 1H), 7.89-7.96 (m, 2H); 13 CNMR (100 MHz, CDCl 3 ): d = 44.9, 45.3, 115.4 (d, J =

Ligand‐free palladium‐catalyzed tandem pathways for the synthesis of 4,4‐diarylbutanones and 4,4‐diaryl‐3‐butenones under microwave conditions

“…[7] Moreover, β-substituted carbonyl compounds are the backbone of active biomolecules, such as enokipodine B (fungal biomarker) or paroxetine (antidepressant). [11] Synthetic methods used for the preparation of β-arylketones are usually based on a coupling between methyl vinyl ketone (MVK) and various aryl reagents in the presence of palladium catalysts. [12][13][14][15][16][17][18][19] Further functionalization, leading to appropriate β-diarylketones, can be performed using synthetic tools that form a new carbon-carbon bond: the Heck reaction [20][21][22][23] or the reductive Heck reaction (conjugate addition).…”

“…They can also be used in the production of fluorescent probes or optical materials . Moreover, β‐substituted carbonyl compounds are the backbone of active biomolecules, such as enokipodine B (fungal biomarker) or paroxetine (antidepressant) . Synthetic methods used for the preparation of β‐arylketones are usually based on a coupling between methyl vinyl ketone (MVK) and various aryl reagents in the presence of palladium catalysts .…”

Progress in the Synthesis of C(sp2)—C(sp3) Bond by Reductive Heck Reactions of Alkenes

“…纳米钯催化的交叉偶联反应可用于构建碳碳键 [39] . 由于纳米钯催化剂具有较大的比表面积, 因此该类转化 [40] 报道了纳米钯催化的芳基碘与共轭烯酮的分子间 还原 Heck 反应(Eq. 15).…”

Palladium-Catalyzed Cyclobutanation of Aryl Sulfonates through both C–O and C–H Cleavage

“…Herein, we report such a reaction to achieve the cyclobutanation of phenol derivatives (Scheme B). Our strategy toward the transformation is based on Heck-type reactions, which have been widely employed in transition-metal-catalyzed addition, reduction, and difunctionalization of alkenes. , During the reaction, the key point is to overcome the β-hydride elimination of Heck-type intermediate C generated in situ (Scheme ). Thus, species C can further undergo intramolecular ligand exchange to generate D , followed by reductive elimination to produce the target product.…”