Regio‐ and Enantioselective Silane‐Terminated Intramolecular Heck Reactions

Tietze, Lutz F.; Schimpf, Ralph

doi:10.1002/anie.199410891

Cited by 92 publications

(15 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Variations of base, palladium source and temperature proved ineffective in acetonitrile solvent, with some product being observed with the less hindered base diethylamine replacing triethylamine, and the use of PdCl 2 (PPh 3 ) 2 rather than Pd 2 (dba) 3 , but a satisfactory yield was never obtained. Upon moving to the less polar solvent DMF, efficient cyclisation was observed with this base/palladium source combination even at room temperature, and by extending the reaction time an optimum combination was found to be DMF solvent with diethylamine as base, with palladium dichloride bis(triphenylphosphine) as the catalyst source with a reaction time of 5 h. Under these conditions the Heck reaction proceeded to give an 86% yield of 1-allyl-3-methylene-indan-1-ol 4 with no significant by-products.…”

Section: Introductionmentioning

confidence: 85%

“…Although DMF is the more common solvent for the Heck reaction it is surprising that such a difference is noted between the solvents, especially given the precedent [6] for the efficiency of acetonitrile in cyclisation to a five-membered ring in another system. In the cases (entries [1][2][3][4] where no yield is given for product the starting material is recovered essentially unchanged, and thus it appears to be the initial oxidative insertion into the aryl iodide which is retarded in these cases rather than the cyclisation itself, hence it is difficult to see why variations in the reactivity of substrate alkenes could cause the apparent differences. The difference in polarity between acetonitrile (l = 3.92, e = 38) and DMF (l = 3.82, e = 37) is not great enough to explain the difference in reactivity, so other, substrate specific, factors may be important.…”

Section: Introductionmentioning

confidence: 95%

“…Recently it has been shown that there is good selectivity in the asymmetric Heck reaction to give silane terminated alkenes, presumably reflecting the lability of the a-silyl hydrogen towards elimination [3].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Desymmetrisation of a diallyl system by intramolecular Heck reaction

Coogan

Pottenger

2005

Journal of Organometallic Chemistry

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 85%

Section: Introductionmentioning

confidence: 95%

See 1 more Smart Citation

Desymmetrisation of a diallyl system by intramolecular Heck reaction

Coogan

Pottenger

2005

Journal of Organometallic Chemistry

View full text Add to dashboard Cite

“…Most strategies circumvent this challenge by employing conjugated or heteroatom-substituted olefins that drive β-hydrogen elimination away from the newly formed stereocenter. The first example of enantioselective functionalization of an acyclic olefin was reported by Tietze for an olefin bearing a trimethylsilyl group at the allylic position (Figure 2C) [24]. The elimination of this electrofuge group is favored over the elimination towards the newly formed stereocenter, rendering the desilylated chiral compound 8a as the major product.…”

Section: Migratory Insertion and β-Eliminationmentioning

confidence: 96%

Mechanistically guided survey of enantioselective palladium-catalyzed alkene functionalization

Bahamonde

2021

Trends in Chemistry

View full text Add to dashboard Cite

Palladium-catalyzed alkene functionalization was discovered more than 60 years ago and is now a commonly used strategy for the synthesis of pharmaceuticals and materials. The development of asymmetric variants of this reaction is described in this short review. The review is organized around the mechanistic challenges that have hampered the development of these transformations for various substrate classes, as well as the strategies, ligand classes, and additives that have been introduced to overcome them. New methodologies for Heck, oxidative Heck, dehydrogenative Heck, and Wacker-type reactions are highlighted, with a special focus on the progression from cyclic to acyclic to electronically unbiased olefin substrates.Historical background: Mizoroki-Heck-and Wacker-type chemistry Palladium-catalyzed methodologies are ubiquitous in synthetic chemistry and key to their successful implementation has been obtaining a detailed mechanistic understanding of these reactions. Specifically, the two-electron nature of oxidative addition (see Glossary) and reductive elimination, facile β-hydrogen elimination, and high π-Lewis acidity have enabled the organometallic community to rationally design a myriad of Pd-catalyzed strategies to efficiently build molecular complexity [1][2][3][4][5][6][7][8]. The versatility of Pd catalysis has been described in many reviews [9][10][11][12][13][14], but herein we focus on Pd-mediated enantioselective functionalization of alkenes. In particular, this review highlights the different strategies developed to control the regio-and stereoselectivity of the key elementary steps in these processes.The discovery of the Pd(II)-catalyzed water addition to ethylene to give acetaldehyde by researchers in Wacker Chemie in 1959 [15,16] inspired numerous chemists to study the use of transition-metal complexes to catalyze organic transformations. Shortly after, in 1970, the laboratories of Mizoroki and Heck reported the use of Pd(0) complexes to promote olefin arylations and alkylations [17,18]. The general mechanism of Heck-type transformations is outlined in Figure 1 (Key figure), where a Pd(0) complex (A) engages in oxidative addition with an alkenyl or aryl halide to generate Pd(II) intermediate B. Migratory insertion of the alkene into the Pd-C bond forges the new C−C bond and yields Pd-alkyl intermediate C. Subsequently, a β-hydrogen elimination delivers the alkene product 3, and a base-mediated reductive elimination of the Pd-hydride species (D) regenerates the Pd(0) catalyst to restart the cycle. Key to the development of asymmetric variants of this transformation is to favor the β-hydrogen elimination of H b , away from the newly formed stereocenter to render chiral product 3a, over H a , which would deliver achiral product 3b. Although early Heck reaction development attracted the attention of numerous research groups, asymmetric variants of these methodologies remained elusive until 1989, when the groups of Overman and Shibasaki described the use of bisphosphine HighlightsThe mechanistic rat...

show abstract

“…Furthermore, we describe some interesting observations that show that the outcome of the Heck cyclization of N-(2-iodobenzoyl)-g-amino-a,b-unsaturated esters and related compounds depends on the experimental conditions and the structure of the substrate. During the development of this project, [7,10] the synthesis of isoquinoline derivatives using intramolecular Heck reaction has been reported by the groups of Tietze, [11] Goff, [12] Gibson, [13] and De Mesmaeker. [14] Results and Discussion…”

Section: Introductionmentioning

confidence: 99%

Efficient Synthesis of Chiral Isoquinoline and Pyrido[1,2-b]-isoquinoline Derivatives via Intramolecular Heck Reactions

2001

View full text Add to dashboard Cite

The palladium(0)‐catalyzed reaction of derivatives of γ‐amino‐α,β‐unsaturated esters bearing an N‐(2‐iodobenzoyl) substituent results in an intramolecular Heck reaction, the outcome of which depends on the structure of the substrate as well as on the experimental conditions. The methodology developed has been applied to the efficient syntheses of chiral isoquinoline and pyrido[1,2‐b]–isoquinoline derivatives.

show abstract

Regio‐ and Enantioselective Silane‐Terminated Intramolecular Heck Reactions

Cited by 92 publications

References 18 publications

Desymmetrisation of a diallyl system by intramolecular Heck reaction

Desymmetrisation of a diallyl system by intramolecular Heck reaction

Mechanistically guided survey of enantioselective palladium-catalyzed alkene functionalization

Efficient Synthesis of Chiral Isoquinoline and Pyrido[1,2-b]-isoquinoline Derivatives via Intramolecular Heck Reactions

Contact Info

Product

Resources

About