The [4 + 4] cycloaddition and its strategic application in natural product synthesis

Sieburth, Scott McN.; Cunard, Nicholas T.

doi:10.1016/0040-4020(95)01077-7

Cited by 116 publications

(40 citation statements)

References 161 publications

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“…It should be noted that the formation of 8-membered ring is not easy. 9,10 Here the structure of 2h was also unambiguously established by X-ray diffraction studies (Figure 2). 11 Again, the N-tether substrate 1i with two methyl groups installed at the terminal position of allene moiety afforded the bicyclic products 2i and 2i' in a combined yield of 76%, with a ratio of 2i/2i' being ≥92∶8.…”

Section: Scheme 1 Schemementioning

confidence: 89%

The [2+2]‐Cycloaddition Reaction of Bisallenes: A Dramatic Substituent Effect

Lü

2010

Chin. J. Chem.

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The bisallenes 1 possessing a phenylsulfonyl or n-butyl substituent at the internal position of allene moieties could be smoothly transformed to the bicyclo[5.2.0] or bicyclo[6.2.0] derivatives 2 in moderate to excellent yields with good regioselectivity upon refluxing in toluene. This [2＋2]-cycloaddition reaction shows an interesting substituent effect as unveiled by comparing with the results of unsubstituted substrates. However, further attention should be paid to the control of the regioselectivity of the [2＋2]-cycloaddition involving different C＝C bonds.

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Section: Scheme 1 Schemementioning

confidence: 89%

The [2+2]‐Cycloaddition Reaction of Bisallenes: A Dramatic Substituent Effect

Lü

2010

Chin. J. Chem.

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“…The cycloaddition of butadienes is one of the most successful transformations of this type 1d. 3 However, many attempts toward the synthesis of functionalized oligomers (i.e. telomerization) by using Ni catalysts resulted in the formation of mixtures of products 1b.…”

Section: Ni‐catalyzed Regioselective Coupling Of 13‐dienes With Grigmentioning

confidence: 99%

Nickel‐Catalyzed Dimerization and Carbosilylation of 1,3‐Butadienes with Chlorosilanes and Grignard Reagents

et al. 2003

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Ni0 reacts with 1,3-butadienes to form octadienediyl-nickel complexes, which play an important role as key intermediates in the oligomerization of butadienes. [1,2] This reaction demonstrates extreme synthetic utility as a straightforward method for the formation of C 8 building blocks in organic synthesis. The cycloaddition of butadienes is one of the most successful transformations of this type. [1d, 3] However, many attempts toward the synthesis of functionalized oligomers (i.e. telomerization) by using Ni catalysts resulted in the formation of mixtures of products. [1b, 4] We have recently developed new methods for the regioselective addition of silicon and/or carbon functionalities to alkenes or dienes in the presence of early-transition-metal catalysts, such as zirconium complexes [5] and titanium complexes. [6] During the course of these studies, we found that Ni catalyzes the dimerization and carbosilylation of butadienes in the presence of chlorosilanes and Grignard reagents to give rise to 1,6-dienes with high regio-and stereoselectivity [Eq. (1)].When a catalytic amount of [Ni(acac) 2 ] (0.05 mmol; acac = acetylacetone) was added to a solution of isoprene (2 mmol), chlorotriethylsilane (1 mmol), and nBuMgCl (1.2 mmol) in THF (1.3 mL) at À20 8C, and the resulting mixture was stirred for a further 18 hours at the same temperature, compound 1, with Et 3 Si and nBu groups at positions 3 and 8 of its dimerized isoprene skeleton, was isolated in 87 % yield (E/Z = 76:24) from the crude mixture by HPLC, with CHCl 3 as the eluent ( (dppp = propane-1,

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“…( Figure 1). [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] In addition to these strategies, a third possible approach is the formation of bicycles via transannular cyclizations ( Figure 2).…”

Section: Introductionmentioning

confidence: 99%

Construction of Bicyclic Ring Systems via a Transannular SmI₂-Mediated Ketone−Olefin Cyclization Strategy

2007

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The development of novel methods and strategies for the formation of polycyclic ring structures is of utmost importance in organic synthesis. The present study describes the investigation of a transannular cyclization strategy for constructing bicyclic ring systems. To test the viability of the approach, the SmI2-mediated ketone-olefin coupling reaction, a method previously developed in this laboratory, was examined. Investigation of the transannular cyclization of cyclooctene, cyclodecene, and cycloundecene derivatives revealed that the process proceeds with high yield and diastereoselectivity, and in the case of larger ring-sized compounds, with excellent regioselectivity. The regioselectivity of the annulation process could be rationalized based on examining the low energy conformations of the keto alkene starting materials. These results demonstrate the efficiency and the potential of the transannular cyclization tactic for the creation of bicyclic ring systems.

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The [4 + 4] cycloaddition and its strategic application in natural product synthesis

Cited by 116 publications

References 161 publications

The [2+2]‐Cycloaddition Reaction of Bisallenes: A Dramatic Substituent Effect

The [2+2]‐Cycloaddition Reaction of Bisallenes: A Dramatic Substituent Effect

Nickel‐Catalyzed Dimerization and Carbosilylation of 1,3‐Butadienes with Chlorosilanes and Grignard Reagents

Construction of Bicyclic Ring Systems via a Transannular SmI₂-Mediated Ketone−Olefin Cyclization Strategy

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The [4 + 4] cycloaddition and its strategic application in natural product synthesis

Cited by 116 publications

References 161 publications

The [2+2]‐Cycloaddition Reaction of Bisallenes: A Dramatic Substituent Effect

The [2+2]‐Cycloaddition Reaction of Bisallenes: A Dramatic Substituent Effect

Nickel‐Catalyzed Dimerization and Carbosilylation of 1,3‐Butadienes with Chlorosilanes and Grignard Reagents

Construction of Bicyclic Ring Systems via a Transannular SmI2-Mediated Ketone−Olefin Cyclization Strategy

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Construction of Bicyclic Ring Systems via a Transannular SmI₂-Mediated Ketone−Olefin Cyclization Strategy