The ‘Hirao reduction’ revisited: a procedure for the synthesis of terminal vinyl bromides by the reduction of 1,1-dibromoalkenes

Abbas, Sahar; Hayes, Christopher J.; Worden, Stephen

doi:10.1016/s0040-4039(00)00353-1

Cited by 67 publications

(30 citation statements)

References 11 publications

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“…Bromodienes 1a and 1b were prepared as described in the Supplementary Information. The synthesis of 1-bromo-3-methyl-4-phenyl-1,3-butadiene 1c and 1-bromo-4-phenylbutadiene 1d was adapted from a known procedure [17] and is detailed in the Supplementary Information. GC analysis were performed with a GC Agilent Technologies 6890N instrument.…”

Section: Experimental Section General Remarksmentioning

confidence: 99%

“…Interestingly, when the coupling reaction was carried out with bromodiene 1d, [17] which consisted in a 2 : 1 mixture of E : Z bromoolefins, we observed double bond isomerization to obtain the corresponding (E,E)-aminodiene as a pure stereiosomer when morpholine 2a was used (entry 8), and a 3 : 1 ratio of the (E,E) and (Z,E) isomers, respectively, when the reaction was carried out with Nmethylaniline 2b (entry 9). [18] Clearly, in both cases the less stable (Z)-enamines undergo isomerization into the more stable (E) isomers.…”

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confidence: 99%

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Palladium‐Catalyzed Amination of 1‐Bromo‐ and 1‐Chloro‐1,3‐butadienes: A General Method for the Synthesis of 1‐Amino‐1,3‐butadienes

et al. 2004

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1-Amino-1,3-butadienes, interesting substrates for [4 þ 2] cycloadditions, are prepared by Pd-catalyzed cross-coupling of secondary amines with readily available 1-halodienes. The optimized catalytic system employs Pd 2 (dba) 3 as metal source and XPHOS as supporting ligand. The reaction proceeds in very high yields with 1-bromo-1,3-butadienes, and also with the less reactive 1-chloro-1,3-butadienes. Moreover, the range of amines that can be incorporated includes aromatic amines, and cyclic and acyclic aliphatic amines.

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Section: Experimental Section General Remarksmentioning

confidence: 99%

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confidence: 99%

Palladium‐Catalyzed Amination of 1‐Bromo‐ and 1‐Chloro‐1,3‐butadienes: A General Method for the Synthesis of 1‐Amino‐1,3‐butadienes

et al. 2004

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“…Noncommercial enones S2, S3, S4, S5, S6, S7, S9, S10, and S11 were prepared according to reported procedures (see the Supporting Information). the aldehyde to the dibromide by the Ramirez protocol [10] and bromine abstraction by dimethylphosphite, in the presence of triethylamine, afforded E/Z mixtures of desired alkenyl bromides (Table 1). [10] Heating the bromides in a solution of NaOH in isopropanol at reflux induces the elimination of the Z isomer affording a separable mixture of the terminal alkyne and the pure E isomer ( Table 1).…”

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confidence: 99%

“…the aldehyde to the dibromide by the Ramirez protocol [10] and bromine abstraction by dimethylphosphite, in the presence of triethylamine, afforded E/Z mixtures of desired alkenyl bromides (Table 1). [10] Heating the bromides in a solution of NaOH in isopropanol at reflux induces the elimination of the Z isomer affording a separable mixture of the terminal alkyne and the pure E isomer ( Table 1). [11] The abstraction of the bromide and the elimination of the (Z)-bromide were carried out on the crude mixtures.…”

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confidence: 99%

Formation of Quaternary Stereogenic Centers by Copper‐Catalyzed Asymmetric Conjugate Addition Reactions of Alkenylaluminums to Trisubstituted Enones

Müller

Alexakis

2013

Chemistry A European J

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Alkenylaluminums undergo asymmetric copper-catalyzed conjugate addition (ACA) to β-substituted enones allowing the formation of stereogenic all-carbon quaternary centers. Phosphinamine-copper complexes proved to be particularly active and selective compared with phosphoramidite ligands. After extensive optimization, high enantioselectivities (up to 96% ee) were obtained for the addition of alkenylalanes to β-substituted enones. Two strategies for the generation of the requisite alkenylaluminums were explored allowing for the introduction of aryl- and alkyl-substituted alkenyl nucleophiles. Moreover, alkyl-substituted phosphinamine (SimplePhos) ligands were identified for the first time as highly efficient ligands for the Cu-catalyzed ACA.

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“…Their use as precursors to vinyl anions, 12) and as coupling partners in a wide range of transition metal-mediated coupling reactions, 13) has stimulated a great deal of interest. There have been several reports about the stereoselective synthesis of (E)-and (Z)-b-bromostyrene isomers, [14][15][16][17][18] but the application of these synthetic methods to diazirinyl compounds was not reported. The simple synthesis of diazirinyl (E)-and (Z)-b-bromostyrene have been required in the stereoselective preparation of conjugated photoreactive polyene and enynes.…”

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confidence: 99%

Stereoselective Synthesis of (E)- and (Z)-.BETA.-Bromostyrene Containing Trifluoromethyldiazirine for Photoaffinity Labeling

Hashimoto

Komano

Nabeta

et al. 2005

CHEMICAL & PHARMACEUTICAL BULLETIN

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Photoaffinity labeling is a powerful method in the study of biological structures and functions. 1,2) The method is suitable for the analysis of biological interactions based on the affinity of ligands to receptors. Various photophores, such as phenyldiazirine, arylazide, and benzophenone have been used. Comparative irradiation studies of these three photophors in living cells suggested that a carbene precursor (3-trifluoromethyl)phenyldiazirine is the most promising for in vivo applications.3) However, the complicated synthesis of the diazirinyl ring has resulted in fewer applications for the diazirines in biomolecular studies than other photophors. We have already established the first versatile approach to simplify the time-consuming methods currently used for diazirine synthesis, by starting from only a few simple diazirines, e.g. m-methoxy-phenyldiazirine, which can be synthesized on a large scale. 4) Direct substitution on phenyldiazirines (post-functional modification) gave a family of substituted phenyldiazirines without the need to repeat all the steps of diazirine synthesis from the beginning.5-7) Some tags are needed on photophor to detect photolabeled components. Radiolabeled photophors are used for high sensitive detection. But the synthesis and handling of radiolabeled compounds is quite complicated. We have attempted to resolve these difficulties with a combination of avidin-biotin systems (photoaffinity biotinylation). 8,9) The recent development of mass spectrometry has enabled us to identify important structures in target biomolecules. 10) Elucidation of the different mass numbers, derived from a mixture of unlabeled and stable-isotope labeled photophors, may be useful to identify a photolabeled ligand-biomolecule complex on the MS spectrum. However, to the best of our knowledge, a few protocols for the synthesis of a stable-isotope labeled diazirinyl photophor have been reported. 11) b-Bromostyrenes are extremely useful intermediates in organic synthesis. Their use as precursors to vinyl anions, 12) and as coupling partners in a wide range of transition metal-mediated coupling reactions, 13) has stimulated a great deal of interest. There have been several reports about the stereoselective synthesis of (E)-and (Z)-b-bromostyrene isomers, [14][15][16][17][18] but the application of these synthetic methods to diazirinyl compounds was not reported. The simple synthesis of diazirinyl (E)-and (Z)-b-bromostyrene have been required in the stereoselective preparation of conjugated photoreactive polyene and enynes. The conventional synthesis of b-bromostyrene isomers requires reduction steps which may also reduce diazirinyl nitrogen-nitrogen double bond. Here, we would like to describe the first effective, stereoselective synthesis of diazirinyl b-bromostyrenes from diazirinyl aldehyde 1a, b, 5,6) and deuterium introductions to diazirinyl b-bromostyrenes, with commercially available reagents.To achieve the stereoselective synthesis of diazirinyl bbromostyrene, diazirinyl b,b-dibromostyrenes, 2a, b may b...

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The ‘Hirao reduction’ revisited: a procedure for the synthesis of terminal vinyl bromides by the reduction of 1,1-dibromoalkenes

Cited by 67 publications

References 11 publications

Palladium‐Catalyzed Amination of 1‐Bromo‐ and 1‐Chloro‐1,3‐butadienes: A General Method for the Synthesis of 1‐Amino‐1,3‐butadienes

Palladium‐Catalyzed Amination of 1‐Bromo‐ and 1‐Chloro‐1,3‐butadienes: A General Method for the Synthesis of 1‐Amino‐1,3‐butadienes

Formation of Quaternary Stereogenic Centers by Copper‐Catalyzed Asymmetric Conjugate Addition Reactions of Alkenylaluminums to Trisubstituted Enones

Stereoselective Synthesis of (E)- and (Z)-.BETA.-Bromostyrene Containing Trifluoromethyldiazirine for Photoaffinity Labeling

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