Halomethylmetal compounds

Seyferth, Dietmar; Shih, Houng-Min; Mazerolles, P.; Lesbre, M.; Joanny, M.

doi:10.1016/s0022-328x(00)85284-5

Cited by 17 publications

(13 citation statements)

References 8 publications

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“…In previous papers of this series we have described the insertion of dichlorocarbene derived by thermolysis of phenyl(bromodichloromethyl)mercury into C-H linkages, including those of aliphatic-and alkyl-substituted aromatic hydrocarbons,3 of aliphatic ethers,4 and of tetraalkyl derivatives of silicon, germanium, and tin. [6][7] The observed relative reactivities of tertiary, secondary, and primary C-H bonds to CC12 insertion and the nature of the groups which activated such insertion processes (a-aryl, -alkoxy, a-vinyl, ß-trialkylmetal) led us to propose transition state I for such insertion reactions. If such a simple three-center transition state X + /cr:xH ^\ / cA, were indeed involved, then one might expect that such…”

Section: Methodsmentioning

confidence: 99%

“…Satisfactory pmr and ir spectra were also obtained. 6 The product contains 1-2% of a ring-contracted isomer. c The product contains ~10% of a ring-contracted isomer.…”

Section: Ch3°bxmentioning

confidence: 99%

“…Journal of the American Chemical Society / 95:20 / October °MVK, methyl vinyl ketone; EA, ethylideneacetone; CH, 2-cyclohexenone. 6 All products were either compared with authentic samples or exhibited spectral data in accordance with the assigned structures. All new products yielded the correct elemental analyses.…”

Section: Ch3°bxmentioning

confidence: 99%

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Hydroboration. XXXV. Cyclic hydroboration of 2,4-dimethyl-1,4-pentadiene and 2,5-dimethyl-1,5-hexadiene. Simple synthesis of bis(3,5-dimethyl)borinane and bis(3,6-dimethyl)borepane and their application to the 1,4-addition reaction of organoboranes

Negishi¹,

Brown²

1973

J. Am. Chem. Soc.

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The hydroboration of 2,4-dimethyl-l ,4-pentadiene (2,4-DMP) or 2,5-dimethyl-l,5-hexadiene (2,5-DMH) with borane in THF at 0°in the molar ratio of 1:1 with the diene-to-borane mode of addition is rapid and complete immediately following the addition of diene. The oxidation product derived from 2,4-DMP consists of a 98:2 mixture of 2,4-dimethyl-l ,5-pentanediol and its isomer, while that from 2,5-DMH is a 90:10 mixture of the 1,6-diol and its isomer. Little or no position isomerization occurs at 25°, but at 70°a slow isomerization is evident in the product from 2,5-DMH. The initial hydroboration mixture contains only ca. 50% of either bis(3,5-dimethyl)borinane (3,5-DMBN) or bis(3,6-dimethyl)borepane (3,6-DMBP). The presence of fully alkylated polymeric species, presumably the 3:2 dumbbell-shaped products, and unreacted borane in THF is indicated. The amount of 3,5-DMBN or 3,6-DMBP increases with time, requiring approximately 24 hr at 25°or 1 hr at 70°to attain the maximum yields of 90-94 % (3,5-DMBN) or 75% (3,6-DMBP). Consequently, the hydroboration of 2,4-DMP or 2,5-DMH with borane in THF in the molar ratio of 1:1 followed by a brief heating of the reaction mixture at reflux provides a simple synthesis of 3,5-DMBN or 3,6-DMBP. 3,5-DMBN has been isolated and identified. 3,6-DMBP has not been isolated, but has been fully identified. The dimeric nature of these compounds has been established by the typical bridge absorption in the ir at 1650-1565 cm-1. Treatment of these compounds with alcohols produces the corresponding B-alkoxy derivatives. The hydroboration of olefins with a solution in THF containing a modest excess of 3,5-DMBN or 3,6-DMBP proceeds smoothly, requiring approximately 1 hr with 1-hexene, 1-octene, isobutylene, 2-butene, cyclopentene, and norbornene, 2 hr with 2-methyl-2-butene, 4-8 hr with cyclohexene, and 16-24 hr with 2,3-dimethyl-2-butene. The hydroboration products containing B-alkyl-3,5-DMBN or B-alkyl-3,6-DMBP can in most cases be used for further operations following quenching of residual hydride. Distillation provides B-alkyl-3,5-DMBN (98-99 % pure) or B-alkyl-3,6-DMBP (~90% pure) in excellent yields. Alternatively, the reaction of B-methoxy-3,5-DMBN with alkyllithium produces the corresponding B-alkyl-3,5-DMBP in excellent yields. These B-alkylboracyclanes undergo a facile reaction with methyl vinyl ketone and similar ,ß-unsaturated carbonyl derivatives to transfer the B-alkyl group from boron to carbon, especially readily when the B-alkyl group is secondary or tertiary. This extension of the 1,4addition reaction via organoboranes to highly branched secondary and tertiary alkyl groups makes this reaction broadly applicable to the formation of carbon-carbon bonds utilizing alkyl and cycloalkyl groups with a wide range of structures.

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Section: Methodsmentioning

confidence: 99%

“…Satisfactory pmr and ir spectra were also obtained. 6 The product contains 1-2% of a ring-contracted isomer. c The product contains ~10% of a ring-contracted isomer.…”

Section: Ch3°bxmentioning

confidence: 99%

See 1 more Smart Citation

Hydroboration. XXXV. Cyclic hydroboration of 2,4-dimethyl-1,4-pentadiene and 2,5-dimethyl-1,5-hexadiene. Simple synthesis of bis(3,5-dimethyl)borinane and bis(3,6-dimethyl)borepane and their application to the 1,4-addition reaction of organoboranes

Negishi¹,

Brown²

1973

J. Am. Chem. Soc.

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“…Dihalocarbene setzen sich mit gespannten Ringsystemen sowohl unter Ringerweiterung als auch unter Insertion in die ß-C-H-Bindung um [2,3,6]. Bei fünf-und sechsgliedrigen Sila-, Germa-und Stannacycloalkanen tritt der zuletzt genannte Fall ausschließlich ein [4,5]. Bei Heterocycloaliphaten mit Übergangsmetallen verlaufen Insertionen von Schwefeldioxid, Kohlenmonoxid und Kohlendioxid, unabhängig von der Ringgröße, nur unter Ringerweiterung [7][8][9][10][11].…”

unclassified

Darstellung und Eigenschaften von und Reaktionen mit metallhaltigen Heterocyclen, XLVII [1]. Einschiebungsreaktionen von phasentransferkatalytisch in situ erzeugten Dihalocarbenen in P-haltige Manganacycloalkane – Struktur und chemisches Verhalten der Reaktionsprodukte / Preparation and Properties of and Reactions with Metal-Containing Heterocycles, XLVII [1]. Insertion Reactions of Phase-Transfer-Catalytically in situ Generated Dihalocarbenes into P-Containing Manganacycloalkanes – Structure and Chemical

Lindner

Zinsser

Mayer

et al. 1985

Zeitschrift Für Naturforschung B

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Abstract The phase-transfer-catalytically in situ generated dihalocarbenes CCl2 and CBr2 are inserted into a β-C-H bond of the five-and six-membered phosphamanganacycloalkanes (OC)4[xxx] (1a, b) [n = 1(a), 2(b)] to give the functionalized metallacycles (OC)4[xxx](2a, a′, b, b′) [X = Cl: n = 1(a), 2(b); X = Br: n = 1(a′), 2(b′)]. 2b crystallizes in the orthorhombic space group Pbca with Z = 8 and has a distorted chair conformation with equatorial position of the CHCl2 group. The envelope conformation of 2a in solution was elucidated by means of 1H and 13C{1H} NMR spectroscopic investigations.

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“…In benzene at 90°and in chloroform6 at 25°, 1 gives diphenylacetylene (2) as the main product (85-90%), nitrogen, and p-toluenesulfinic acid, without formation of 2-tosyl-2,2-diphenyl-l-diazoethane (3) or the decomposition products expected from 3 (Chart I). (2) (a) L. Caglioti, A. Dondoni, and G. Rosini, Chim.…”

mentioning

confidence: 99%

Diphenylacetylene from the decomposition of 2,2-diphenyl-1-tosylazoethylene

Rosini¹,

Cacchi²

1972

J. Org. Chem.

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Halomethylmetal compounds

Cited by 17 publications

References 8 publications

Hydroboration. XXXV. Cyclic hydroboration of 2,4-dimethyl-1,4-pentadiene and 2,5-dimethyl-1,5-hexadiene. Simple synthesis of bis(3,5-dimethyl)borinane and bis(3,6-dimethyl)borepane and their application to the 1,4-addition reaction of organoboranes

Hydroboration. XXXV. Cyclic hydroboration of 2,4-dimethyl-1,4-pentadiene and 2,5-dimethyl-1,5-hexadiene. Simple synthesis of bis(3,5-dimethyl)borinane and bis(3,6-dimethyl)borepane and their application to the 1,4-addition reaction of organoboranes

Diphenylacetylene from the decomposition of 2,2-diphenyl-1-tosylazoethylene

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