A Palladium‐Catalyzed Domino Coupling Process Leading to Annelated Pentafulvenes

Dyker, Gerald; Nerenz, F.; Siemsen, Peter; Bubenitschek, Peter; Jones, Peter G.

doi:10.1002/cber.19961291019

Cited by 29 publications

(9 citation statements)

References 19 publications

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“…We believe this to be the first structural study of a 2H-benz[cd]azulene; the only relevant previous report of which we are aware describes the palladium-coupled bis(suberene) system, 30, which, as shown in Figure 4, possesses a benz[cd]azulene substructure. [18] Scheme 5. Reactions of benz[cd]azulenes with TCNE and with organometallic reagents.…”

Section: H Nmr Chemical Shifts Of the H(3) And H(5) Resonances Inmentioning

confidence: 99%

A Convenient Synthetic Route to Benz[cd]azulenes: Versatile Ligands with the Potential To Bind Metals in an η⁵, η⁶, or η⁷ Fashion

Balduzzi

Müller‐Bunz

McGlinchey

2004

Chemistry A European J

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Section: H Nmr Chemical Shifts Of the H(3) And H(5) Resonances Inmentioning

confidence: 99%

A Convenient Synthetic Route to Benz[cd]azulenes: Versatile Ligands with the Potential To Bind Metals in an η⁵, η⁶, or η⁷ Fashion

Balduzzi

Müller‐Bunz

McGlinchey

2004

Chemistry A European J

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“…[23] The striking difference between the reactions of allenes 8 a ± e and 8 f ± g with p-toluenesulfonic acid can be explained by the fact that cyclization would lead to a strained unsaturated 5,5,6-ring system. [24] In addition, the antiaromatic character of the 9-fluorenyl cation in the ground state and the rigid character of the ketone-derived subunits of 8 f and 8 g are presumed to direct the course of the reaction. [25] Variation of the silyl enol ether in our new allene synthesis was studied next.…”

Section: Resultsmentioning

confidence: 99%

“…After the mixture had been stirred for 48 h, the products were isolated according to the procedure for the preparation of 1. 37,126.36,127.65,128.21,128.31,129.23 (CH,Ph),136.58,137.85 (C,Ph) 24,125.34,127.80,128.13,128.38,128.47 (CH,Ph),136.89,137.57 (C,Ph) 0.96,1.00 (s,9 H;tBu),2.00,2.02 (q,J 9 Hz,3 H;CH 3 ),5.42,5.87 (s,1 H;7.10 ± 7.60 (m,5 H;Ph); 13 C NMR (CDCl 3 , 50 MHz): d C À 3.36, À 4.34 (Me 2 Si), 18.34, 18.09 (C, CMe 3 ), 24.19,19.55 (CH 3 ),25.89,25.59 (CH 3 , CMe 3 ), 108. 16,125.15,125.82,126.17,126.69,128.04,128.33 (CH,Ph),136.89,137.60 (C,Ph),149.41,151.43 (C,COSi).…”

Section: Preparation Of 2-quinolylacetonementioning

confidence: 99%

Direct Transformation of Silyl Enol Ethers into Functionalized Allenes

Langer¹,

Döring²,

Seyferth³

et al. 2001

Chem. Eur. J.

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The first elimination reactions of silyl enol ethers to lithiated allenes are reported. These reactions allow a direct transformation of readily available silyl enol ethers into functionalized allenes. The action of three to four equivalents of lithium diisopropylamide (LDA) on silyl enol ethers results in the formation of lithiated allenes by initial allylic lithiation, subsequent elimination of a lithium silanolate, and finally, lithiation of the allene thus formed. Starting with amide-derived silyl imino ethers, lithiated ketenimines are obtained. A variety of reactions of the lithiated allenes with electrophiles (chlorosilanes, trimethylchlorostannane, dimethyl sulfate and ethanol) were carried out. Elimination of silanolate is observed only for substrates that contain the hindered SiMe2tBu or Si(iPr)3 moiety, but not for the SiMe3 group. The reaction of 1,1-dilithio-3,3-diphenylallene with ketones provides a convenient access to novel 1,1-di(hydroxymethyl)allenes which undergo a domino Nazarov-Friedel-Crafts reaction upon treatment with p-toluenesulfonic acid.

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“…An unusual C-H activation on ortho-methoxy groups was observed by Dyker et al [372,373] in the reaction of methoxyiodoarenes such as 240 leading elegantly to 6H-dibenzo [b,d] (242) with various aryl halides gave the benzocyclobutene derivatives 243, the formation of which also involves an alkyl C-H activation [372e].…”

Section: Brmentioning

confidence: 99%

Cross‐Coupling of Organyl Halides with Alkenes – The Heck Reaction

Bräse¹,

Meijere²

2013

Metal‐Catalyzed Cross‐Coupling Reactions and More

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The carbopalladation of an alkene by an organylpalladium halide is the essential step in one of the major contemporary metal-catalyzed C-C coupling reactions. About 45 years ago, a Japanese and an American group almost simultaneously designed and executed palladium-mediated coupling reactions of aryl and alkenyl halides with alkenes [1]. In subsequent investigations, Richard Heck and his group developed this reaction into a catalytic transformation and started to demonstrate its usefulness as well as its rather broad scope. The real push to utilize this powerful C-C-bondforming process, however, started only around the mid-1980s, and by now, an impressive number of publications have established the meanwhile so-called Heck reaction [2] 1) as an indispensable method in Organic Synthesis [3][4][5][6][7]. The universal recognition of the importance of the Heck reaction and the Negishi as well as the Suzuki coupling eventually won the Nobel Prize for Richard Heck along with Ei-ichi Negishi and Akira Suzuki in 2010. The applications of the Heck reaction range from the preparation of -functionalized and unfunctionalized -hydrocarbons, novel polymers, and dyes to new advanced enantioselective syntheses of natural products and biologically active nonnatural compounds. The more or less simultaneous developments of mechanistically related variants, namely, the Kumada, Suzuki, Stille, Hiyama, and Negishi coupling reactions (Chapters 12, 2, 3, 4, and 15, respectively) of metallated alkenes and arenes with aryl and alkenyl halides or the metal-catalyzed formation and cycloisomerization of enynes have drawn profit from the improvement of and mechanistic insights into the Heck reaction. This, of course, applies vice versa as well. Using only a catalytic amount of a palladium(0) complex or a precursor to a palladium species, the Heck reaction can bring about unprecedented structural changes, particularly when conducted intramolecularly. The full potential of this palladium-catalyzed process is still being further explored as demonstrated by a total of over 7000 publications in the past 40 years by 1) The alkynylation of aryl and alkenyl halides, frequently also considered as Heck reactions, is described in Chapter 6.

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A Palladium‐Catalyzed Domino Coupling Process Leading to Annelated Pentafulvenes

Abstract: Annelated pentafulvenes 2, 10, 13, and 14 are efficiently accessible by a palladium‐catalyzed domino coupling process of aryl substituted vinylic bromides 1, 9, 11, and 12, 5‐Membered palladacycles 3 are discussed as key intermediates.

Cited by 29 publications

References 19 publications

A Convenient Synthetic Route to Benz[cd]azulenes: Versatile Ligands with the Potential To Bind Metals in an η⁵, η⁶, or η⁷ Fashion

A Convenient Synthetic Route to Benz[cd]azulenes: Versatile Ligands with the Potential To Bind Metals in an η⁵, η⁶, or η⁷ Fashion

Direct Transformation of Silyl Enol Ethers into Functionalized Allenes

Cross‐Coupling of Organyl Halides with Alkenes – The Heck Reaction

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A Palladium‐Catalyzed Domino Coupling Process Leading to Annelated Pentafulvenes

Abstract: Annelated pentafulvenes 2, 10, 13, and 14 are efficiently accessible by a palladium‐catalyzed domino coupling process of aryl substituted vinylic bromides 1, 9, 11, and 12, 5‐Membered palladacycles 3 are discussed as key intermediates.

Cited by 29 publications

References 19 publications

A Convenient Synthetic Route to Benz[cd]azulenes: Versatile Ligands with the Potential To Bind Metals in an η5, η6, or η7 Fashion

A Convenient Synthetic Route to Benz[cd]azulenes: Versatile Ligands with the Potential To Bind Metals in an η5, η6, or η7 Fashion

Direct Transformation of Silyl Enol Ethers into Functionalized Allenes

Cross‐Coupling of Organyl Halides with Alkenes – The Heck Reaction

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A Convenient Synthetic Route to Benz[cd]azulenes: Versatile Ligands with the Potential To Bind Metals in an η⁵, η⁶, or η⁷ Fashion

A Convenient Synthetic Route to Benz[cd]azulenes: Versatile Ligands with the Potential To Bind Metals in an η⁵, η⁶, or η⁷ Fashion