Notes - Reactions of Sodium Phenylacetylide and Sodium Alkoxide with Tosyl and Mesyl Azides

Boyer, J; Mack, Charles H.; Goebel, Neal C.; Morgan, Lawrence A.

doi:10.1021/jo01101a604

Cited by 96 publications

(44 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[1][2][3] Several attempts at preparing the title compounds were unsuccessful or led to unwanted products. [4][5][6] For example, the reaction of (phenylethynyl)sodium or alkyl-1-ynyllithiums and tosyl azide yielded only 1,2,3-triazole derivatives instead of the target compounds. 7, 8 Even in the case of generating 1-azido-2-phenylethyne (2) in situ, the sequential chemistry of such a shortlived intermediate is still unclear (Scheme 1).…”

Section: Introductionmentioning

confidence: 99%

Ab Initio Study of Molecular Properties and Decomposition Products of 1-AzidoalkynesA Challenge for Experimentalists

2007

View full text Add to dashboard Cite

In this publication, a characterization of different azidoalkyne compounds using high-level ab initio quantum chemical methods is presented. For this purpose, the molecular structures and the 13C NMR chemical shifts have been calculated at the MP2 and CCSD(T) level of theory and the influence of zero-point vibration as well as the solvent on the chemical shifts are discussed. Furthermore, a comparison of the energy barriers of the decomposition under N2 separation for a set of 1-azidoalkynes with different functional groups has been carried out. The molecular structures and properties of the resultant decomposition products have been investigated. It is remarkable that large deviations of the NMR chemical shifts of ethylthioethynyl azide occur in comparison to the experiment. These deviations are far outside of the error bars. Electron correlation effects are of high importance if an accurate description of the chemical shifts of 1-azidoalkynes shall be obtained. A comparison of the energy barriers of the decomposition under N2 separation of 1-azidoalkynes with different functional groups indicates that the stability of 1-azidoalkynes is not increased by typical donor or acceptor groups but rather by silyl or phenyl substituents. The molecular geometries of the decomposition products indicate that the equilibrium structures are of carbene character. Some of the results presented here are in contradiction to previous experimental publications and cast a new light on some open challenges for experimentalists.

show abstract

Section: Introductionmentioning

confidence: 99%

Ab Initio Study of Molecular Properties and Decomposition Products of 1-AzidoalkynesA Challenge for Experimentalists

2007

View full text Add to dashboard Cite

show abstract

“…Anhydrous THF was distilled over sodium/benzophenone ketyl and dichloromethane was distilled over calcium hydride. Methanesulfonyl azide was prepared by reaction of methanesulfonyl chloride (MsN 3 ) with sodium azide 15 and was not distilled. Unless otherwise stated, all chemicals were purchased from the Aldrich Chemical Co. (Milwaukee, WI).…”

Section: Methodsmentioning

confidence: 99%

Enantioselective carbon‐‐hydrogen insertion is an effective and efficient methodology for the synthesis of (r)‐(‐)‐baclofen

Doyle

2002

Chirality

View full text Add to dashboard Cite

A highly enantioselective methodology for the synthesis of the GABA(B) receptor agonist (R)-(-)-baclofen is described. This synthesis begins with p-chlorophenethyl alcohol and involves a catalytic carbon-hydrogen insertion reaction of a chiral dirhodium(II) carboxamidate with the corresponding diazoacetate (81% yield, 95% ee). Subsequent steps convert the intermediate gamma-lactone to (R)- (-)-baclofen in a 60% overall yield. The amount of catalyst required for the C-H insertion transformation is only 0.5 mol%.

show abstract

“…Then Et 3 N (0.88 mL, 6.3 mmol, 1.2 equivs.) was added, followed by addition of methanesulfonyl azide [17] (0.76 g, 6.3 mmol, 1.2 equivs. ), and the reaction was allowed to stir for an additional 24 h. The resulting brown solution was concentrated under reduced pressure and purified by flash chromatography on silica gel (67:33 hexane:ethyl ether) to afford diazoacetoacetate 7 as a pale yellow oil; yield: 1.54 g (4.00 mmol, 74 % yield).…”

Section: (2s3s5r6r)-56-dimethoxy-56-dimethyl-2-propargyloxymethymentioning

confidence: 99%

Stereoselectivity in Metal Carbene Addition to a Carbon‐Carbon Triple Bond Tied to the Reactant Diazoacetate Through a Chiral Linker

2006

View full text Add to dashboard Cite

Abstract:The trajectory of a carbon-carbon triple bond onto a metal carbene for cyclopropene formation is opposite to that of a carbon-carbon double bond in the same system. Diazoacetates prepared from the butane-2,3-diacetals (BDA) of (l)-and (d)-threitol were employed to examine diastereoselectivity in cyclopropenation. The absolute configuration of the predominant isomer was opposite in intramolecular metal carbene additions to propargyl and allyl substituents. Diastereoselectivities in the dirhodium(II) carboxamidate-catalyzed diazo decomposition reactions are as high as 99:1 with match/mismatch selectivites for substrate and catalyst, dependent on catalyst configuration, and are favored in the order:The reactions catalyzed by the Cu-A C H T U N G T R E N N U N G (CH 3 CN) 4 PF 6 /PhBox system produce the same set of diastereoisomers in a complimentary match/mismatch selectivity that also reaches 99:1.

show abstract

Notes - Reactions of Sodium Phenylacetylide and Sodium Alkoxide with Tosyl and Mesyl Azides

Cited by 96 publications

References 2 publications

Ab Initio Study of Molecular Properties and Decomposition Products of 1-AzidoalkynesA Challenge for Experimentalists

Ab Initio Study of Molecular Properties and Decomposition Products of 1-AzidoalkynesA Challenge for Experimentalists

Enantioselective carbon‐‐hydrogen insertion is an effective and efficient methodology for the synthesis of (r)‐(‐)‐baclofen

Stereoselectivity in Metal Carbene Addition to a Carbon‐Carbon Triple Bond Tied to the Reactant Diazoacetate Through a Chiral Linker

Contact Info

Product

Resources

About