1,2-Dihalogenalkenes: Useful Linchpins to Unsaturated Compounds via Palladium or Nickel Catalysis

Alami, Mouâd; Peyrat, Jean-François; Brion, Jean‐Daniel

doi:10.1055/s-2000-7594

Cited by 37 publications

(6 citation statements)

References 95 publications

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“…This technique has been used to introduce a methyl group during the synthesis of methoprene (265) according to the C 10 + C 4 + C 1 pattern; the substitution of the methyl group for the OAc group in compound 266 occurred with complete retention of the initial configuration. (E,Z )-258 f. Cross-coupling involving 1,2-dihaloethenes The (E )-and (Z )-isomers of 1,2-dichloroethene (267) can serve as convenient and inexpensive synthons for the preparation of conjugated dienes (as well as styrenes, enynes and so forth) (see a review 280 ). By varying the conditions and catalysts, it is possible to perform consecutive coupling of these compounds, first, with a saturated and then, a vinylic component (or vice versa), 281 resulting in the formation of the target dienes in high yields and with high isomeric purity.…”

Section: Mgbr + Br Ph 247mentioning

confidence: 99%

“…It is of interest that 1,2-dibromoethene is much less effective in this type of process. 280 g. Synthesis of 1,3-dienes from alkynes and allenes As noted above, alkynes can be used in the cross-coupling instead of alkenes. The reactions of terminal alkynes or their metallated derivatives with alkenyl halides (the Sonogashira reaction, see a review, 282 and transformation of 213 into 214 in general Scheme 8) yield conjugated enynes, which can be reduced to dienes (the reduction techniques are described in Section VII).…”

Section: Mgbr + Br Ph 247mentioning

confidence: 99%

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Synthetic methodologies for carbo-substituted conjugated dienes

Васильев¹,

Serebryakov²

2001

Russ. Chem. Rev.

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We report the observation of changes in the wave turbulence properties of gravitycapillary surface waves due to a finite-depth effect. When the fluid depth is decreased, a hump is observed on the wave spectrum in the capillary regime at a scale that depends on the depth. The possible origin of this hump is discussed. In the gravity regime, the wave spectrum still shows a power law but with an exponent that strongly depends on the depth. A change in the scaling of the gravity spectrum with the mean injected power is also reported. Finally, the probability density function of the wave amplitude rescaled by its rms value is found to be independent of the fluid depth and to be well described by a Tayfun distribution.

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Section: Mgbr + Br Ph 247mentioning

confidence: 99%

Section: Mgbr + Br Ph 247mentioning

confidence: 99%

Synthetic methodologies for carbo-substituted conjugated dienes

Васильев¹,

Serebryakov²

2001

Russ. Chem. Rev.

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“…The focus of this review will thus be the functionalization of 1,2-dihaloalkenes through metal-catalyzed cross-coupling reactions. The last review concerning this topic dates back to 2000, 2 and great progress has been made in this field since then. After briefly presenting methods for the preparation of 1,2-dihaloalkenes (Section 2), this paper will highlight advances from 2000 to 2017 in metal-catalyzed reactions on 1,2-dihaloalkenes to form C-C (Section 3) or C-heteroatom bonds (Section 4).…”

Section: Introductionmentioning

confidence: 99%

1,2-Dihaloalkenes in Metal-Catalyzed Reactions

et al. 2018

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1,2-Dihaloalkenes readily undergo simultaneous or sequential difunctionalization through transition-metal-catalyzed reactions, which makes them attractive building blocks for complex unsaturated motifs. This review summarizes recent applications of such transformations in C–C and C–heteroatom bond forming processes. The facile synthesis of stereodefined alkene derivatives, as well as aromatic and heteroatomic compounds, from 1,2-dihaloalkenes is thus outlined.1 Introduction2 Synthesis of 1,2-Dihaloalkenes3 C–C Bond Forming Reactions4 C–Heteroatom Bond Forming Reactions5 Conclusion

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“…14 Accordingly, Rossi and coworkers 15 described the utilization of tetrasubstituted (E)- (1) and (E)-tamoxifen (2). Palladium-Catalyzed Double Cross-Coupling of E-vinylic Dibromides Vol.…”

Section: Introductionmentioning

confidence: 99%

Palladium-catalyzed double cross-coupling of E-vinylic dibromides with PhZnCl and the synthesis of tamoxifen

Pilli¹,

Robello²

2004

J. Braz. Chem. Soc.

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Compostos (E)-1,2-dibromo vinílicos 11a-f foram preparados estereosseletivamente via reação de bromação de alcinos empregando-se tribrometo de piridínio em MeOH/CCl 4 a baixa temperatura e utilizados na reação de duplo acoplamento com PhZnCl catalisada por Pd(0), segundo protocolo de Negishi, fornecendo as respectivas olefinas tri e tetrassubstituídas 14a-e. Tamoxifeno, um agente antiestrogênico de uso clínico na terapia do câncer de mama, foi preparado na forma de uma mistura Z:E de proporção 2.3:1, em 7 etapas em um rendimento global de 30% a partir do 4-iodofenol (3).(E)-1,2-vinylic dibromides 11a-f were stereoselectively prepared via bromination of acetylenic compounds with pyridinium tribromide in MeOH/CCl 4 at low temperature and double crosscoupled with PhZnCl under Pd(0) catalysis (Negishi protocol) to afford tri-and tetrasubstituted olefins 14a-e. Tamoxifen, a selective estrogen receptor modulator clinically prescribed in breast cancer therapy, was prepared in 7 steps and 30% overall yield from 4-iodophenol (3) as a 2.3:1 mixture of (Z)-and (E)-isomers. Keywords: (E)-1,2-vinylic dibromides, double cross-coupling, palladium catalysis, tri-and tetrasubstituted olefins, tamoxifen IntroductionThe stereoselective synthesis of tri-and tetrasubstituted olefins is of great interest in the domain of biologically active compounds where the E and Z isomers may have completely different biological properties as represented by tamoxifen, a tetrasubstituted stilbene which acts as a selective estrogen receptor modulator (SERM): while (Z)-tamoxifen (1) displays antiestrogenic activity and is prescribed as the corresponding citrate as an adjuvant for breast cancer therapy, (E)-isomer 2 has estrogenic activity and stimulates the proliferation of hormone-responsive breast cancer cells (Figure 1). 1 Methods are available for the separation of (E)-and (Z)-isomers as well as for isomerization of estrogenic (E)-tamoxifen (2) 2 to antiestrogenic (Z)-tamoxifen (1), [3][4][5] including large scale operations. Among the routes already described in the literature, the method by Knochel and coworkers 6 is by far the more efficient one: starting from 1-phenyl-1-butyne, (Z)-tamoxifen (1) is prepared in three steps and 71% yield via Ni(II)-catalyzed syn carbozincation, followed by Negishi coupling of the corresponding vinylic iodide with 4-triisopropylsililoxyphenylzinc bromide.Despite the different approaches already reported for the stereoselective synthesis of tamoxifen (dehydration, 4 McMurry 5 and metal-catalyzed coupling protocols 6-13 ), we were attracted by the possibility of preparing (Z)-tamoxifen (1) from the corresponding (E)-1,2-vinylic dibromide via an one-pot tandem coupling with a phenylorganometallic species with retention of configuration.1,2-Dihaloalkenes are potentially useful starting materials for the preparation of tri-and tetrasubstituted olefins via transition metal catalyzed cross-coupling with organometallic species. 14 Accordingly, Rossi and coworkers 15 described the utilization of tetrasubstituted (E)- ...

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1,2-Dihalogenalkenes: Useful Linchpins to Unsaturated Compounds via Palladium or Nickel Catalysis

Cited by 37 publications

References 95 publications

Synthetic methodologies for carbo-substituted conjugated dienes

Synthetic methodologies for carbo-substituted conjugated dienes

1,2-Dihaloalkenes in Metal-Catalyzed Reactions

Palladium-catalyzed double cross-coupling of E-vinylic dibromides with PhZnCl and the synthesis of tamoxifen

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