Intramolecular cyclizations of acetylenic grignard reagents

Richey, Herman G.; Rothman, Alan M.

doi:10.1016/s0040-4039(01)98978-6

Cited by 53 publications

(9 citation statements)

References 19 publications

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“…Attempts to prepare the methanesulfonate derivative of alcohol 2 resulted in the formation of ( , )- (8). The structure of this material was established by its ready hydrolysis to A-styrylbenzamide (9) and by its ozonization to benzaldehyde and A-formylbenzamide (10). Recrystallization of a sample of 8 from methanol afforded equal quantities of A-styrylbenzamide and (£)-1,4-diphenyl-1 -methoxy-2-azabutadiene (11).…”

Section: Resultsmentioning

confidence: 99%

“…Further support for the structure of ether 8 was obtained by its ready hydrolysis of A'-styrylbenzamide (9). To a solution containing 60 mg of 8 in 25 mL of tetrahydrofuran was added 15 mL of a 10% hydrochloric acid solution.…”

Section: Experimental Section47mentioning

confidence: 99%

“…Thus, a sample containing 100 mg of 8 in 1 mL of methanol was heated until it dissolved. The white solid which precipitated on cooling was identified as A'-styrylbenzamide (9). Concentration of the mother liquors afforded 60 mg of an extremely labile oil which could not be purified further as a result of its hydrolytic instability.…”

Section: Experimental Section47mentioning

confidence: 99%

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Photochemical transformations of small-ring heterocyclic compounds. 99. 1,4-Substituent shifts in the photorearrangement of 2-hydroxymethyl-2H-azirine derivatives to N-Vinylimines

Padwa¹,

Carlsen²,

Tremper³

1978

J. Am. Chem. Soc.

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Section: Resultsmentioning

confidence: 99%

Section: Experimental Section47mentioning

confidence: 99%

Section: Experimental Section47mentioning

confidence: 99%

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Photochemical transformations of small-ring heterocyclic compounds. 99. 1,4-Substituent shifts in the photorearrangement of 2-hydroxymethyl-2H-azirine derivatives to N-Vinylimines

Padwa¹,

Carlsen²,

Tremper³

1978

J. Am. Chem. Soc.

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“…Reductive intramolecular cyclization of acetylenic halides has been a subject of long-standing mechanistic and synthetic interest to organic chemists. [1][2][3][4][5][6][7][8][9][10][11] An excellent illustration of this process is provided by 6-bromo-1-phenyl-1-hexyne which, when treated with tri-n-butyltin hydride (Bu 3 SnH) in the presence of a trace amount of 2,2Јazobis(2-methylpropionitrile) (AIBN) in refluxing benzene for 36 h, affords benzylidenecyclopentane in essentially quantitative yield. [4] As a complement to earlier research on the chemically promoted intramolecular cyclization of acetylenic halides, we demonstrated in our laboratory that direct electrochemical reduction of such compounds at both mercury and carbon cathodes results in cleavage of the carbon-halogen bond, which produces an alkyl radical that cyclizes to form an ylidenecycloalkane.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Reduction of Phenyl‐Conjugated Acetylenic Halides by Nickel(I) Salen: Cyclization versus Coupling

et al. 2007

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Cyclic voltammetry and controlled-potential electrolysis were employed to study the catalytic reduction of five phenyl-conjugated haloalkynes by nickel(I) salen electrogenerated at carbon cathodes in dimethylformamide containing tetramethylammonium tetrafluoroborate. Electrocatalytic reduction of 7-bromo-and 7-iodo-1-phenyl-1-heptyne affords the carbocyclic product, benzylidenecyclohexane, in up to 41 % yield, whereas under similar conditions reduction of 5-halo-1-phenyl-1-pentyne and 8-bromo-1-phenyl-1-octyne gives benzylidenecyclobutane and benzylidenecycloheptane, respectively, in very low yield (Յ1 %). Dimers, alkynes, and alkenynes are other products formed from the phenyl-

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“…Classically, hydroxy groups on propargylic alcohols are used in uncatalyzed carbomagnesiation (Scheme 5) [60–61]. This addition proceeded in an anti fashion to give intermediate 2a .…”

Section: Reviewmentioning

confidence: 99%

Recent advances in transition-metal-catalyzed intermolecular carbomagnesiation and carbozincation

Murakami¹,

Yorimitsu²

2013

Beilstein J. Org. Chem.

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SummaryCarbomagnesiation and carbozincation reactions are efficient and direct routes to prepare complex and stereodefined organomagnesium and organozinc reagents. However, carbon–carbon unsaturated bonds are generally unreactive toward organomagnesium and organozinc reagents. Thus, transition metals were employed to accomplish the carbometalation involving wide varieties of substrates and reagents. Recent advances of transition-metal-catalyzed carbomagnesiation and carbozincation reactions are reviewed in this article. The contents are separated into five sections: carbomagnesiation and carbozincation of (1) alkynes bearing an electron-withdrawing group; (2) alkynes bearing a directing group; (3) strained cyclopropenes; (4) unactivated alkynes or alkenes; and (5) substrates that have two carbon–carbon unsaturated bonds (allenes, dienes, enynes, or diynes).

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Intramolecular cyclizations of acetylenic grignard reagents

Cited by 53 publications

References 19 publications

Photochemical transformations of small-ring heterocyclic compounds. 99. 1,4-Substituent shifts in the photorearrangement of 2-hydroxymethyl-2H-azirine derivatives to N-Vinylimines

Photochemical transformations of small-ring heterocyclic compounds. 99. 1,4-Substituent shifts in the photorearrangement of 2-hydroxymethyl-2H-azirine derivatives to N-Vinylimines

Catalytic Reduction of Phenyl‐Conjugated Acetylenic Halides by Nickel(I) Salen: Cyclization versus Coupling

Recent advances in transition-metal-catalyzed intermolecular carbomagnesiation and carbozincation

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