Silafunctional compounds in organic synthesis. Part 20. Hydrogen peroxide oxidation of the silicon-carbon bond in organoalkoxysilanes

Tamao, Kohei; Ishida, Noriaki; Tanaka, Tatsu; Kumada, Makoto

doi:10.1021/om50005a041

Cited by 539 publications

(201 citation statements)

References 1 publication

(3 reference statements)

Supporting

Mentioning

195

Contrasting

Unclassified

Order By: Relevance

“…However, we found that a little-used protocol utilizing acidic conditions by introduction of acetic anhydride served to furnish the desired hydroxyl ketone, isolated after conversion to the acetate. 26 The reasons for the difficulty in obtaining clean oxidation are not obvious for this substrate, though the increased stability of the 6-membered ring silacycle relative to acyclic or 5-membered substrates-together with the steric interactions from the significant substitution about the silacycle-may play an important role.…”

Section: Homo-and Bishomopropargylic Alcohol Substratesmentioning

confidence: 98%

An Alkyne Hydrosilylation-Oxidation Strategy for the Selective Installation of Oxygen Functionality

2005

View full text Add to dashboard Cite

Alkynes bearing propargylic, homopropargylic, and bis-homopropargylic hydroxyl groups are shown to serve as precursors for ketone or α-hydroxy ketone functionality. The approach hinges on the intermediacy of vinylsilanes created through regioselective hydrosilylation catalyzed by the complex [Cp*Ru(MeCN) 3 ]PF 6 . Several oxidative pathways of linear and cyclic vinylsilanes are studied, and the possibility of diastereoselective epoxidation of cyclic vinylsilanes is demonstrated. The sequences constitute the equivalent of stereoselective aldol, homo-aldol, and bishomo-aldol type processes. The method is applied to a short synthesis of the piperidine alkaloid, spectaline.

show abstract

Section: Homo-and Bishomopropargylic Alcohol Substratesmentioning

confidence: 98%

An Alkyne Hydrosilylation-Oxidation Strategy for the Selective Installation of Oxygen Functionality

2005

View full text Add to dashboard Cite

show abstract

“…'H NMR (200 MHz, CDC1,) (in some sections of the NMR spectrum, the diastereoisomers of 246 could be distinguished and are designated as maj (major) and min (minor) 6: 7.45-7.10 (1 OH, m, 24a ("R"), 24a ("S"), 24b), 6.25 (lH, dd, J = 16.0 and 7.0 Hz, 24a ("R")), 6.23 (lH, dd, J = 16.0 and 6.5 Hz, 24a ("S")), 6.17 (lH, dd, J = 18.5 and 6.0 Hz, 24bmaj), 6.16 (lH, dd, J = 18.5 and 6.0 Hz, 24bmin), 6.12 (lH, d, J = 16.0 Hz, 24a ("R"), 240 ("S")), 5.61 (lH, dd, J = 18.5 and 1.5 Hz, Nbmin), 5.60 (lH, dd, J = 18.5 and 1.5 Hz, Nbmaj), 4.18 (lH, d, J = 6.0 Hz, 24b), 3.21 (3H, s, 24b), 3.20 (3H, s, 24a ("R"), 24a ("S")), 2.72 (lH, m, 240 ("R"), 240 ("S"), 2&), 2.23 (3H, s, 240 ("R"), 240 ("S")), 2.22 (3H, s, 24b), 2.10 (2H, m, 24a ("R"), 24a ("S"), 24b), 1.73 (lH, qn, J = 6.5 Hz, 24a ("S")), 1.70 (lH, qn, J = 7.0 Hz, 24a ("R")), 1.33 (3H, d, J = 7.0 Hz, 24b), 1.10 (3H, d, J = 7.0 Hz, 24a ("S")), 1.08 (3H, d, J = 6.0 Hz, 24a ("R")), 1.04 (3H, d, J = 6.5 Hz, 240 ("R"), 240 ("S")), 1.00 (3H, d, J = 6.5 Hz, 24b), -0.02 and -0.03 (6H, 4s, 2&), -0.05 (3H, S, 240 ("S")), -0.07 (6H, s, 24a ("R")), -0.08 (3H, s, 24a ("S")).…”

Section: Cinnarnyldirnethyl-[l'-(r)-methyl-2'-(s)-phenyl-2-rnethoxyetmentioning

confidence: 99%

“…Such an approach has also been used to control stereoselectivity in the alkylations of benzylic silane 7 (5). The alkylated derivatives 8 could then be transformed into alcohols 9 (>95% ee) via oxidative cleavage of the carbon-silicon bond with retention of stereochemical integrity (6). To extend the scope of this method we decided to investigate the alkylations of chiral silylcinnamyl carbanions.…”

Section: Introductionmentioning

confidence: 99%

Chiral organosilicon compounds in synthesis. Preparation and stereoselective alkylations of silylcinnamyl carbanions

Lamothe¹,

Cook²,

Chan³

1992

Can. J. Chem.

View full text Add to dashboard Cite

Silylallyl carbanions of type 13 bearing a chiral lithium complexing substituent remote from silicon can be alkylated regio- and stereoselectively at the α-position by small electrophiles in nonpolar solvents. The regiochemical outcome of the reaction was found to be highly dependent on the size of the incoming electrophile. Secondary alkyl halides react preferentially at the γ-center and good levels of stereoselectivity are still obtained in nonpolar solvents despite the rather long distance between the reacting center and the chiral auxiliary. Transformation of the alkylated allylsilanes into optically active alcohols and carboxylic acids may represent a potential synthetic application of the method.

show abstract

“…Oxidation of this mixture under Tamao−Fleming conditions delivered ethyl ketone in 65% yield. 27 The removal of the N-Boc carbamate using 3 M HCl delivered the natural product (±)-gelsemoxonine 167 in 97% yield.…”

Section: Recent Advances In the Total Synthesis Of Relatedmentioning

confidence: 99%

Modern Methods for Total Synthesis of Important Oxindole Alkaloids

Cook¹

2016

Organic Chemistry Insights

View full text Add to dashboard Cite

This review describes the latest synthetic methods found in the literature for the construction of complex natural products containing the spiro[pyrrolidine-3,3′-oxindole] ring system and other oxindoles that are closely related. The spirooxindole system is the central structure of many different types of natural products and synthetic drugs, which are associated with various biological activities. The well-known interest that these compounds inspire in academia, as well as in industry together with our efforts toward the total synthesis of sarpagine-/macroline-related oxindoles inspired us to review this topic. Herein, the strategies used by other expert groups in the field of synthetic organic chemistry and their results are presented in a critical way. The examples were selected on the basis of the elegant way chemists resolved their synthetic challenges. Many other excellent syntheses of complex oxindoles can be found in the literature, but were not included due to the limit in the length of this manuscript.KEY WORDS: spirocyclic oxindoles, oxindole alkaloids, alstonia oxindoles, cross coupling reactions, spirocyclic rearrangements, new synthetic methods CITATION: Fonseca and cook. modern methods for total synthesis of important Oxindole alkaloids.

show abstract

Silafunctional compounds in organic synthesis. Part 20. Hydrogen peroxide oxidation of the silicon-carbon bond in organoalkoxysilanes

Cited by 539 publications

References 1 publication

An Alkyne Hydrosilylation-Oxidation Strategy for the Selective Installation of Oxygen Functionality

An Alkyne Hydrosilylation-Oxidation Strategy for the Selective Installation of Oxygen Functionality

Chiral organosilicon compounds in synthesis. Preparation and stereoselective alkylations of silylcinnamyl carbanions

Modern Methods for Total Synthesis of Important Oxindole Alkaloids

Contact Info

Product

Resources

About