Synthesis of Polyarylated Methanes through Cross‐Coupling of Tricarbonylchromium‐Activated Benzyllithiums

McGrew, Genette I.; Temaismithi, Jesada; Carroll, Patrick J.; Walsh, Patrick J.

doi:10.1002/anie.201000957

Cited by 108 publications

(28 citation statements)

References 31 publications

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“…Consequently, a catalytic cycle in which the lithium reagent 14 participated in the transmetalation step was proposed. Cross-coupling reaction of Cr(CO) 3 -complexed benzyllithiums with aryl bromides was developed as a versatile approach to polyarylated methanes (Scheme 16.5) [9]. When a tetrahydrofuran (THF) solution of Cr-complexed diphenylmethane 15 and aryl bromide was heated at 55-60 • C in the presence of PdCl 2 (PPh 3 ) 2 and lithium hexamethyldisilazide (LiHMDS), triarylmethanes 16 were produced in high to excellent yields.…”

Section: Cross-coupling Reactions Of Organolithium Reagentsmentioning

confidence: 99%

“…Noteworthy, a phenyl-chlorine bond remains intact during the coupling process. Applying the optimized conditions to Cr-complexed toluene 18 provided monoarylated toluenes 19 or diarylated ones 20 selectively depending on aryl bromides employed (Scheme 16.6) [9]. Thus, the coupling of 18 with 2,6-disubstituted bromobenzenes gave 19a and 19b probably due to the steric hindrance of the bromine-attached sp 2 carbon, whereas double arylation of 18 took place with 2,6-unsubstituted and 2-substituted ones, giving rise to 20a-20f.…”

Section: Cross-coupling Reactions Of Organolithium Reagentsmentioning

confidence: 99%

“…In the latter case, the monocoupled intermediate was more reactive than 18 presumably because the acidity of the benzylic hydrogens was enhanced by the first arylation. Furthermore, multiple arylation of Cr-complexed xylene and mesitylene was also demonstrated; some examples (products 21-24) are shown in Scheme 16.7 [9]. When the Cr(CO) 3 -indane complex was subjected to the conditions for double arylation, each arylation proceeded at the opposite face to the Cr-coordinated benzene face to give 24 in 76% yield.…”

Section: Cross-coupling Reactions Of Organolithium Reagentsmentioning

confidence: 99%

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Lithium Compounds in Cross‐Coupling Reactions

Shimizu

2014

Lithium Compounds in Organic Synthesis

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IntroductionTransition-metal-catalyzed cross-coupling reactions of organic halides with organometallic compounds have been recognized as one of the most powerful, practical, and versatile methods for carbon-carbon bond formation [1]. Various organometallic reagents such as organomagnesium (Grignard reagents), -zinc, -tin, -boron, and -silicon compounds are extensively studied and applied to the concise synthesis of natural products, biologically active substances, and functional materials [2]. On the other hand, the cross-coupling reactions of organolithium compounds are less developed compared to those of the organometals listed above probably because the high reactivity of lithium can cause side reactions such as halogen-lithium exchange and deprotonation of organic halides seriously and result in the narrow compatibility of functional groups [3]. Organolithium compounds are often used as typical precursors of the other organometallic reagents. Accordingly, it is highly desirable to use organolithium compounds as nucleophiles directly for transition-metal-catalyzed cross-coupling reactions in view of atom economy as well as the reduction of chemical waste, money, and time. As shown in Scheme 16.1, this chapter is divided into four sections based on the types of lithium compounds that participate in the cross-coupling reactions: (i) organolithium reagents in which a lithium atom is attached to a carbon atom, (ii) lithium enolates, (iii) lithium amides, and (iv) lithium thiolates. Described in Section 16.2 are cross-coupling reactions of aryl-, alkenyl-, and alkyllithiums with halogenated compounds. Section 16.3 summarizes the coupling reactions of lithium enolates with organic halides. Amination of aryl halides with lithium amides is reviewed in Section 16.4. Finally, thioether synthesis by coupling reaction using lithium thiolates as nucleophiles is described in Section 16.5. Throughout this chapter, molecular structures of lithium compounds, their precursors, and the molecular fragments originating from the lithium compounds in the products are drawn with thick bonds and atom labels in bold.

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Section: Cross-coupling Reactions Of Organolithium Reagentsmentioning

confidence: 99%

Section: Cross-coupling Reactions Of Organolithium Reagentsmentioning

confidence: 99%

Section: Cross-coupling Reactions Of Organolithium Reagentsmentioning

confidence: 99%

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Lithium Compounds in Cross‐Coupling Reactions

Shimizu

2014

Lithium Compounds in Organic Synthesis

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“…[1] We, [2] and other research teams, [3] have been interested in the arylation of pronucleophiles bearing weakly acidic C(sp 3 )–H bonds. Under basic reaction conditions the pronucleophile C–H is reversibly deprotonated to generate an organometallic species that undergoes transition metal catalyzed coupling with an aryl halide.…”

Section: Introductionmentioning

confidence: 99%

“…Under basic reaction conditions the pronucleophile C–H is reversibly deprotonated to generate an organometallic species that undergoes transition metal catalyzed coupling with an aryl halide. For example, we have used this approach for the arylation of diarylmethanes to prepare triarylmethanes (Scheme 1A), [4] the arylation of allylbenzenes to prepare 1,1-diaryl prop-2-enes (Scheme 1B), [5] and the arylation of benzylic C–H’s situated alpha to heteroatoms, [2b, 6] which can undergo a subsequent [1,2]-Wittig rearrangement (Scheme 1C). [2b] These reactions generally exhibit very high selectivity for mono-arylations, which is usually due to the increased steric shielding of the remaining benzylic C–H relative to those in the starting materials.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Diarylated 4‐Pyridylmethyl Ethers via Palladium‐Catalyzed Cross‐Coupling Reactions

et al. 2017

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The direct arylation of weakly acidic sp3–hybridized C–H bonds via deprotonated cross–coupling processes (DCCP) is a challenge. Herein, a Pd(NIXANTPHOS)-based catalyst for the mono arylation of 4-pyridylmethyl 2-aryl ethers to generate diarylated 4-pyridyl methyl ethers is introduced. Furthermore, under similar conditions, the diarylation of 4-pyridylmethyl ethers with aryl bromides has been developed. These methods enable the synthesis of new pyridine derivatives, which are common in medicinally active compounds and in application in materials science.

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Pd‐Catalyzed Benzylic CH Functionalization

Thorat¹,

Jain²,

Parganiha³

et al. 2022

Handbook of CH-Functionalization

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Palladium‐catalyzed benzylic CH functionalization has enormous application in industry and academia. Conventional methods have limited scope and selectivity toward functionalization attributed to the very high reactivity of benzylic position particularly benzylic anion. This article discusses the current development of palladium‐catalyzed benzylic CH functionalization involving CC, CO, CN, and CF bond formation which not only tame the reactivity of benzylic anion but also enables its reaction with a large variety of substrates. Some of the applications such as construction of biologically, pharmaceutically, and agrochemical relevant organic molecules have been discussed. This article summarizes palladium‐catalyzed benzylic CH functionalization in a comprehensive way.

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Synthesis of Polyarylated Methanes through Cross‐Coupling of Tricarbonylchromium‐Activated Benzyllithiums

Cited by 108 publications

References 31 publications

Lithium Compounds in Cross‐Coupling Reactions

Lithium Compounds in Cross‐Coupling Reactions

Synthesis of Diarylated 4‐Pyridylmethyl Ethers via Palladium‐Catalyzed Cross‐Coupling Reactions

Pd‐Catalyzed Benzylic CH Functionalization

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