The effect of the trimethylsilylmethyl substituent on ketene cycloadditions

Brady, William T.; CHENG, T. C.

doi:10.1021/jo00424a034

Cited by 14 publications

(5 citation statements)

References 4 publications

(7 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This aldehyde 11 was condensed with the lithium trimethylsilylacetylide to afford 12 as a mixture of diastereomers (1:l). The trimethylsilyl group was removed with KOH at room temperature (21 OC) 19).) This should allow selective protection and release of the appropriate silyl group at the terminus of interest.…”

Section: Resultsmentioning

confidence: 99%

“…This should allow selective protection and release of the appropriate silyl group at the terminus of interest. Thus the synthesis of two suitable building blocks, Z-1 -trimethylsilyl-6-tert-butyldiphenylsilyhex-3-ene-1,5-diyne (18) and Z-l-trimethylsilyl-6-triisopropylsilylhex-3-ene-1,5-diyne (19) was examined. As outlined in Chart 2, these compounds were prepared by repetitive Pd(0) based coupling followed by removal of the trimethylsilyl group in K2C03-methanol.…”

Section: Resultsmentioning

confidence: 99%

“…Abstract: The Pd(0) based synthesis of two disilyl synthons (Z-1-trimethylsilyl-6-tert-butyldiphenylsilylhex-3-ene-1,5-diyne (18) and Z-l-trimethylsilyl-6-triisopropylsilylhex-3-ene-1,5-diyne (19)) and the selective removal of the trimethylsilyl group (K2C03, MeOH) to afford 24 and 25 is described. These building blocks are employed in the construction of the taxamycin-12 compound 38 (16,17,18-trimethyl-2-methyloxymethoxy-9-hydroxybicyc]o [9.3.…”

Section: Introductionmentioning

confidence: 99%

“…R6sum6 : On dCcrit la syntMse, basCe sur l'utilisation du Pd(O), de deux synthons disilyCs (Z-1-trimCthylsilyl-6-tert-butyldiphCnylsilylhex-3-kne-1,5-diyne (18) et Z-1-trimCthylsilyl-6-triisopropylsilylhex-3-kne-1,5-diyne (19)) et l'enlkvement selectif du groupe trimCthylsilyle (K,C03, MeOH) pour conduire aux compos6s 24 et 25. On a utilise ces blocs pour la prCparation du composC 38 (16,17,hydroxybicyclo[9.3.1]pentad~c-5-~ne-3,5-diyne), un dCrive de la taxamycine-12. La cyclisation finale du cycle ?…”

Section: Introductionunclassified

See 3 more Smart Citations

Taxamycins: a new enediyne family with synthetic and biological potential

Lu¹,

Harwig²,

Fallis³

1995

Can. J. Chem.

View full text Add to dashboard Cite

The Pd(0) based synthesis of two disilyl synthons (Z-1-trimethylsilyl-6-tert-butyldiphenylsilylhex-3-ene-1,5-diyne (18) and Z-1-trimethylsilyl-6-triisopropylsilylhex-3-ene-1,5-diyne (19)) and the selective removal of the trimethylsilyl group (K2CO3, MeOH) to afford 24 and 25 is described. These building blocks are employed in the construction of the taxamycin-12 compound 38 (16,17,18-trimethyl-2-methyloxymethoxy-9-hydroxybicyclo[9.3.1]pentadec-5-ene-3,7-diyne). The final ring closure to the 12-membered ring utilizes an intramolecular Cr–Ni mediated condensation of the iodoalkyne 37 (1,3,3-trimethyl-2-(2-oxoethyl)-4-(Z-1-methyloxymethoxy-7-iodohept-4-ene-2,6-diynyl)cyclohexene). Keyword: cancer, enediynes, synthesis, Pd(0) coupling.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionunclassified

See 2 more Smart Citations

Taxamycins: a new enediyne family with synthetic and biological potential

Lu¹,

Harwig²,

Fallis³

1995

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

“…A possible explanation for these trends is the concept of neutral hyperconjugation, 28 which is the reason for the enhanced stability of silyl ketenes. 28,35 The contribution of the zwitterionic resonance structure B to the electronic ground state increases with increasing electron donation of the EPh 3 group, which rises from Si to Pb. Note, however, that the weight of the phosphaketene resonance structure (A) is by far dominant in all compounds.…”

Section: Dalton Transactions Papermentioning

confidence: 99%

Is the phosphaethynolate anion, (OCP)−, an ambident nucleophile? A spectroscopic and computational study

2014

View full text Add to dashboard Cite

The reactivity of Na(OCP) was investigated towards triorganyl compounds of the heavier group 14 elements (R3EX R = Ph or (i)Pr; E = Si, Ge, Sn, Pb; X = Cl, OTf). In the case of E = Si two constitutional isomers were formed and characterised in situ: R3Si-O-C[triple bond, length as m-dash]P is the kinetic and R3Si-P[double bond, length as m-dash]C[double bond, length as m-dash]O is the thermodynamic product, representing experimental evidence of the ambident character of the (OCP)(-) anion. Applying theoretical calculations and spectroscopic methods, the compound previously reported as (i)Pr3Si-O-C[triple bond, length as m-dash]P can now unambiguously be identified as (i)Pr3Si-P[double bond, length as m-dash]C[double bond, length as m-dash]O. The heavier analogues form exclusively the phosphaketene isomer R3E-P[double bond, length as m-dash]C[double bond, length as m-dash]O (E = Ge, Sn, Pb). DFT calculations were performed to gain deeper insight into the bonding and thermodynamic stability of these compounds.

show abstract

The Electrophilic Substitution of Allylsilanes and Vinylsilanes

1989

View full text Add to dashboard Cite

Allylsilanes and vinylsilanes usually react with electrophiles to give substitution. These reactions are conveniently understood as the reactions of alkenes that have been significantly but only slightly modified by the presence of the silyl group. In both reactions, substitution is favored over addition, and both the site of attack and the site of the double bond in the product are usually determined by the site of the silyl group in the starting material. In this chapter only the electrophilic substitution reactions of allylsilanes, vinylsilanes, and allenylsilanes is discussed. It is further restricted to the reactions of tetraorganosilanes because they are synthetically the most interesting in the laboratory. However, although they are not included in the tables, allylsilanes and vinylsilanes that react by addition rather than substitution or that are not tetraorganosilanes are referred to occasionally in the text wherever their reactions illuminate the discussion. Many of the features of the reactions discussed here are shared by the reactions of arylsilanes, ethynylsilanes, propargylsilanes, cyclopropylsilanes, and cyclopropylmethylsilanes. The methods by which allylsilanes and vinylsilanes are synthesized have been summarized in several places. Stereochemsitry of reactions of allenylsilanes and vinylsilanes is discussed. Scope and limitations include discussions of protodesilylation and deuterodesilyation and the use of carbon, nitrogen, and oxygen as electrophiles. Other electrophiles include phosphorus, sulfur, metals, halogens, and selenium. All of these are covered in the extensive tabular material

show abstract

The effect of the trimethylsilylmethyl substituent on ketene cycloadditions

Cited by 14 publications

References 4 publications

Taxamycins: a new enediyne family with synthetic and biological potential

Taxamycins: a new enediyne family with synthetic and biological potential

Is the phosphaethynolate anion, (OCP)−, an ambident nucleophile? A spectroscopic and computational study

The Electrophilic Substitution of Allylsilanes and Vinylsilanes

Contact Info

Product

Resources

About