Cyanoesterification of norbornenes catalyzed by palladium: facile synthetic methodology to introduce cyano and ester functionalities via direct carbon–carbon bond cleavage of cyanoformates

Nishihara, Yasushi; Inoue, Yoshiaki; Izawa, Seisuke; Miyasaka, Mitsuru; Tanemura, Kenki; Nakajima, Kiyohiko; Takagi, Kentaro

doi:10.1016/j.tet.2006.08.025

Cited by 69 publications

(19 citation statements)

References 99 publications

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“…Second generation Grubbs catalyst 1 was purchased from Aldrich Chemical Co., Catalyst 2, 77 polar norbornenes 3a-3g, 78,79 and Ru(H)Cl (CO)(PPh 3 ) 3 , 80 were synthesized according to literature procedures. In a 50-mL stainless steel autoclave purged with argon, 38.0 mg (0.2 mmol) of ROMP polymer 4a and Ru(H)Cl(CO)(PPh 3 ) 3 (1.9 mg, 0.2 3 10 À2 mmol, 1 mol %) were added in 2.0 mL of xylene.…”

Section: Methodsmentioning

confidence: 99%

Synthesis, characterization, and thermal properties of ring‐opening metathesis polynorbornenes and their hydrogenated derivatives bearing various ester and cyano groups

Nishihara

Izawa

Inoue

et al. 2008

J. Polym. Sci. A Polym. Chem.

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Doubly functionalized polar norbornenes 3a–3g substituted by both a variety of ester and cyano groups were polymerized by ring‐opening metathesis polymerization (ROMP) with a Ru carbene complex 2 bearing 3‐bromopyridine as a ligand (third generation Grubbs' catalyst) in a living manner. The successive hydrogenation of the main‐chain double bond in the synthesized living ROMP polymers 4a–4g with a hydridoruthenium complex was exploited. The comparison of thermal properties of a series of ring‐opening metathesis polymers 4a–4g with those of their hydrogenated derivatives 5a–5g revealed the decrease of glass transition temperatures (Tg) but little change of the 5% decomposition temperature (Td5). In all cases examined in this study, a decrease of Tg by hydrogenation was around 20–40 °C, regardless of the ester substitutents. In the presence of the additional PCy3, triethylamine, and methanol after complete consumption of monomer 3a under the living ROMP condition, the tandem ROMP‐hydrogenation of the resulting polymer 4a generated in situ was attained under a H2 (9.8 MPa) atmosphere at 80 °C to afford the hydrogenated polymer 5a, retaining the narrow polydispersity of 1.03. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3314–3325 2008

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Section: Methodsmentioning

confidence: 99%

Synthesis, characterization, and thermal properties of ring‐opening metathesis polynorbornenes and their hydrogenated derivatives bearing various ester and cyano groups

Nishihara

Izawa

Inoue

et al. 2008

J. Polym. Sci. A Polym. Chem.

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“…31,32 Successively, we performed optical resolution of the obtained (6)-1 into (þ)-1 and (-)-1 by high performance liquid chromatography (HPLC) with a chiral stationary phase, Daicel Chiralcel OD-H (id ¼ 10 mm, 25 cm length, flow rate: 2.0 mL/min). Monomer (6)-1 resulted in good enantioseparation using optimal eluents of hexane: 2-propanol (19:1).…”

Section: Resultsmentioning

confidence: 99%

“…31,32 The procedure was convenient and reproducible, giving the product in excellent yield (>90%) and stereochemical purity (>99% exo-fashion). Thus, if optically resolved monomer is obtained, it would be of great interest to evaluate polymerization behavior for the enantiomerically pure norbornene derivatives bearing both cyano and ester groups.…”

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confidence: 99%

Enantioseparation of doubly functionalized polar norbornenes by HPLC and their ruthenium‐catalyzed ring‐opening metathesis polymerization

Nishihara

Doi

Izawa

et al. 2009

J. Polym. Sci. A Polym. Chem.

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Doubly fuctionalized polar norbornenes bearing the cyano and ester groups in 2,3‐positions are synthesized and enantiomers are separated by high performance liquid chromatography (HPLC) with a chiral stationary phase. These optically active monomers are polymerized by ruthenium carbene catalysts, and high yields of the polymers were obtained. The chiral monomer bearing ethyl ester gave an optically active polymer of lower, but opposite sign of optical rotation (monomer [α]D = +61.0°, polymer [α]D = −3.1°). The circular dichroism (CD) of the obtained chiral polymers gave a Cotton effect. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 485–491, 2010

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“…In particular, carbocyanation of an unsaturated π moiety via C–CN bond activation provides a unique approach to prepare nitrile compounds. 92 Since the early work of intermolecular coupling between arylnitriles and internal acetylenes by Hiyama and Nakao in 2004, 93 a variety of nitrile derivatives, such as allylnitriles, 94 carbonocyanidates, 95 carbamoyl cyanides, 96 alkynylnitriles, and alkenylnitriles were demonstrated to be well compatible for such a “cut and sew” transformation. In addition, the carbocyanation reaction also proceeded in an intramolecular fashion, 93b,96a–b,97 where use of chiral ligands provided the cyclization products with high enantioselectivities.…”

Section: Less Strained Compoundsmentioning

confidence: 99%

“Cut and Sew” Transformations via Transition-Metal-Catalyzed Carbon–Carbon Bond Activation

et al. 2017

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The transition metal-catalyzed “cut and sew” transformation has recently emerged as a useful strategy for preparing complex molecular structures. After oxidative addition of a transition metal into a carbon–carbon bond, the resulting two carbon termini can be both functionalized in one step via the following migratory insertion and reductive elimination with unsaturated units, such as alkenes, alkynes, allenes, CO and polar multiple bonds. Three- or four-membered rings are often employed as reaction partners due to their high ring strains. The participation of non-strained structures generally relies on cleavage of a polar carbon–CN bond or assistance of a directing group.

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Cyanoesterification of norbornenes catalyzed by palladium: facile synthetic methodology to introduce cyano and ester functionalities via direct carbon–carbon bond cleavage of cyanoformates

Cited by 69 publications

References 99 publications

Synthesis, characterization, and thermal properties of ring‐opening metathesis polynorbornenes and their hydrogenated derivatives bearing various ester and cyano groups

Synthesis, characterization, and thermal properties of ring‐opening metathesis polynorbornenes and their hydrogenated derivatives bearing various ester and cyano groups

Enantioseparation of doubly functionalized polar norbornenes by HPLC and their ruthenium‐catalyzed ring‐opening metathesis polymerization

“Cut and Sew” Transformations via Transition-Metal-Catalyzed Carbon–Carbon Bond Activation

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