Lewis acid-catalyzed trans-carbosilylation of alkynes with propargyl- and allenyltrimethylsilanes

Yoshikawa, Eiji; Kasahara, Masaki; Asao, Naoki; Yamamoto, Yoshinori

doi:10.1016/s0040-4039(00)00650-x

Cited by 28 publications

(6 citation statements)

References 9 publications

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“…In particular, carbocupration,1e zirconium-catalyzed carboalumination, nickel-catalyzed carbozincation, allylmetalation of metalated alkynes, allylzirconation, allylgallation, allylmanganation, and alkyllithiation have high synthetic potential due to wide applicability. The addition of different substituted allyl- and propargylsilanes to unactivated alkynes in the presence of catalytic amounts of Lewis Acids was also recently reported …”

Section: Introductionmentioning

confidence: 89%

Stereoselective Preparation of Dienyl Zirconocene Complexes via a Tandem Allylic C−H Bond Activation-Elimination Sequence

2003

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Several dienyl zirconocene derivatives were easily prepared, as unique geometrical isomers, from simple non-conjugated unsaturated enol ethers with (1-butene)ZrCp2 complexes. This new methodology is based on a tandem allylic C-H bond activation-elimination sequence and the mechanism has been mapped out by deuterium labeling experiments. The stereochemical outcome of this process was determined by addition of several electrophiles. Moreover, when the organometallic derivative is vinylic as well as allylic such as in 44-47Zr, an unexpected reversal of the stereochemistry has been found during the zirconium to copper transmetalation step.

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Section: Introductionmentioning

confidence: 89%

Stereoselective Preparation of Dienyl Zirconocene Complexes via a Tandem Allylic C−H Bond Activation-Elimination Sequence

2003

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“…Development of synthetic methods for vinyl allenes has attracted much attention, − since vinyl allenes, which bear a cumulenic and conjugated vinyl functionality, are useful and unique precursors or intermediates in organic synthesis. − Several useful methods have been reported, mainly based on reactions of organometallic reagents with suitably functionalized propargyl derivatives. − …”

Section: Introductionmentioning

confidence: 99%

Preparation of Vinyl Allenes from 1-Lithio-1,3-dienyl Phosphine Oxides and Aldehydes by the Wittig−Horner Reaction

Zhang

Song

et al. 2005

J. Org. Chem.

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[reaction: see text] Vinyl allenes were prepared in high yields by the Wittig-Horner reaction of 1-lithio-1,3-dienyl phosphine oxides with aldehydes. 1-Lithio-1,3-dienyl phosphine oxides were generated in situ from lithiation of 1-iodo-1,3-dienyl phosphine oxides, which were obtained by iodination of alpha-phosphinozirconacyclopentadienes. As a whole, a vinyl allene is synthesized from two different alkynes and one aldehyde.

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“…Here also, no attention was paid to the use of a Lewis acid as an activator for the allylmetalation of unactivated alkynes. We previously reported that Lewis acids such as AlCl 3 , EtAlCl 2 , ZrCl 4 , HfCl 4 , and B(C 6 F 5 ) 3 catalyzed efficiently the intermolecular hydrosilylation, hydrostannation, allylsilylation, and allylstannation 5 of unactivated alkynes to give the corresponding trans -hydro- and allylmetalation products with very high stereoselectivities in high chemical yields (eqs 1 and 2). , The intramolecular version of the Lewis acid catalyzed hydro- and carbometalation produces the corresponding silacycles (eq 3) and carbocycles (eq 4), in which the hydro- and carbosilylation take place also in a trans manner …”

Section: Introductionmentioning

confidence: 99%

Lewis Acid Catalyzed Stereoselective Carbosilylation. Intramolecular trans-Vinylsilylation and trans-Arylsilylation of Unactivated Alkynes

Asao

Shimada

et al. 2001

J. Am. Chem. Soc.

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Intramolecular trans-vinylsilylation using silicon-tethered alkynylvinylsilanes 3b-c was catalyzed dramatically by Lewis acids such as EtAlCl(2) to give the corresponding six-membered silacycles 4b-c in high yields. The reaction proceeded via an exo-mode cyclization. In addition to the vinylsilylation, the intramolecular trans-arylsilylations using carbon-tethered alkynylarylsilanes 8a-b were also catalyzed by Lewis acids such as HfCl(4) to give six- and seven-membered cyclic (E)-vinylsilanes 9a-b, respectively. The cyclization of silicon-tethered substrates 13a-d afforded five- and six-membered silacycle products 14a-d in low to high yields. All arylsilylation reactions proceeded via an exo-mode fashion exclusively.

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Lewis acid-catalyzed trans-carbosilylation of alkynes with propargyl- and allenyltrimethylsilanes

Cited by 28 publications

References 9 publications

Stereoselective Preparation of Dienyl Zirconocene Complexes via a Tandem Allylic C−H Bond Activation-Elimination Sequence

Stereoselective Preparation of Dienyl Zirconocene Complexes via a Tandem Allylic C−H Bond Activation-Elimination Sequence

Preparation of Vinyl Allenes from 1-Lithio-1,3-dienyl Phosphine Oxides and Aldehydes by the Wittig−Horner Reaction

Lewis Acid Catalyzed Stereoselective Carbosilylation. Intramolecular trans-Vinylsilylation and trans-Arylsilylation of Unactivated Alkynes

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