Applications In Natural Product Synthesis Research Articles

A Mild Deoxygenation of Alcohols by Trialkylboranes-Air via Xanthate Esters

This method offers a good alternative for metal hydrides in reductive deoxygenation. The procedure is very mild and especially suitable for applications in natural product synthesis. Besides, it is an excellent way for the introduction of a deuterium label in complex molecules using available and cheap D2O.

Catalytic, Enantioselective, Vinylogous Aldol Reactions

AbstractFor Abstract see ChemInform Abstract in Full Text.

Novel Routes to Pyrroles, Indoles and Carbazoles - Applications in Natural Product Synthesis

Novel Routes to Pyrroles, Indoles and Carbazoles - Applications in Natural Product Synthesis

Catalytic, Enantioselective, Vinylogous Aldol Reactions

In 1935, R. C. Fuson formulated the principle of vinylogy to explain how the influence of a functional group may be felt at a distant point in the molecule when this position is connected by conjugated double-bond linkages to the group. In polar reactions, this concept allows the extension of the electrophilic or nucleophilic character of a functional group through the pi system of a carbon-carbon double bond. This vinylogous extension has been applied to the aldol reaction by employing "extended" dienol ethers derived from gamma-enolizable alpha,beta-unsaturated carbonyl compounds. Since 1994, several methods for the catalytic, enantioselective, vinylogous aldol reaction have appeared, with which varying degrees of regio- (site), enantio-, and diastereoselectivity can be attained. In this Review, the current scope and limitations of this transformation, as well as its application in natural product synthesis, are discussed.

Efficient Routes to Optically Active Azido‐, Amino‐, Di‐azido‐ and Di‐amino‐cyclitols with chiro‐ and allo‐Configuration from myo‐Inositol.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Efficient routes to optically active azido-, amino-, di-azido- and di-amino-cyclitols with chiro- and allo-configuration from myo-inositol

Efficient routes to hitherto unknown 1 d-2,5-di-azido-di-deoxy- allo-inositol, 1 d-2,5-di-amino-di-deoxy- allo-inositol, 1 l-1-azido-1-deoxy- chiro-inositol and 1 l-1-amino-1-deoxy- chiro-inositol were developed by using cheaply available myo-inositol as the starting material. Preliminary investigations on the enzyme inhibitory properties were done. The methodology reported is amenable to gram scale synthesis and thus can find application in natural product synthesis.

Reactions of Carbenoids and Ketenes from α‐Diazocarbonyls and Their Applications in Natural Products Synthesis

AbstractFor Abstract see ChemInform Abstract in Full Text.

Reactions of Carbenoids and Ketenes from α-Diazocarbonyls and Their Applications in Natural Products Synthesis

Reactions of Carbenoids and Ketenes from α-Diazocarbonyls and Their Applications in Natural Products Synthesis

Strained heterocycles in radical chemistry.

Over the last few decades the use of radicals in synthesis has witnessed an explosive growth through introduction of efficient chain and electron-transfer reactions. Strained heterocycles, in particular, have emerged as a highly versatile and readily available class of radical precursors. The generation of carbinyl radicals of heterocycles has resulted in many elegant applications of heteroatom-centered radicals, such as beta fragmentations, cyclizations, and intramolecular hydrogen atom abstractions. Direct electron transfer to strained heterocycles has been realized through the use of arene radical anions. The method combines the virtues of radical and organometallic chemistry to yield useful functionalized organolithium compounds. Epoxides have been opened with high regioselectivity by titanocene(III) reagents in either stoichiometric or catalytic quantities to yield beta-titanoxy radicals. This development has resulted in many new applications in natural product synthesis.

ChemInform Abstract: The B‐Alkyl Suzuki—Miyaura Cross‐Coupling Reaction: Development, Mechanistic Study, and Applications in Natural Product Synthesis

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The B-Alkyl Suzuki-Miyaura Cross-Coupling Reaction: Development, Mechanistic Study, and Applications in Natural Product Synthesis A list of abbreviations can be found at the end of the article.

The development of new reactions that facilitate the creative and efficient synthesis of molecular structures with desirable properties continues to fascinate chemists. The test of a significant contribution is its acceptance over time by the scientific community. The B-alkyl Suzuki-Miyaura cross-coupling reaction appears to be one such reaction. Since its disclosure by Suzuki and Miyaura in 1986, this reaction has been an attractive solution to challenging synthetic problems.

New Developments in the Pauson-Khand Reaction.

Catalytic and asymmetric variations, enones, enynes, and allene as other starting materials, and numerous applications in natural product synthesis are all evidence of the diversity of the Pauson-Khand reaction [Eq. (a)], which now definitely counts among the standard tools of organic synthesis.

ChemInform Abstract: SNAr Based Macrocyclization via Biaryl Ether Formation: Application in Natural Product Synthesis

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: The (4 + 4) Cycloaddition and Its Strategic Application in Natural Product Synthesis

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthetic Transformations of Vinyl and Aryl Triflates

The increasing use of vinyl and aryl trifluoromethanesulfonates (triflates) is due to their facile preparation from carbonyl compounds and phenols. They undergo cross-coupling reactions with organo-metallics as the corresponding organic halides or addition reactions to alkenes and alkynes. Especially in the Heck reaction triflates proved to be superior to halides with respect to regio- and diastereoselectivity. Palladium-catalyzed carbon monoxide insertion of triflates leading to the corresponding esters or amides has found widespread application in natural product synthesis. Various deoxygenation procedures for ketones or phenols are based on the ease of removal of the trifluoromethanesulfoxy group

Palladium-Catalysed Reactions of Organotin Compounds

Palladium-catalysed reactions involving organotin compounds are of rapidly increasing importance in organic synthesis. Carbon-carbon bond formation via cross-coupling reactions is of primary interest in view of the variety of functionalities which can be used. A variety of applications in natural product synthesis have been described, and intramolecular reactions can be used for the formation of small, medium and large rings. Reactions involving additions of tin-element bonds to multiply bonded systems are also of increasing significance. Although «general-purpose» catalysts are available, specific catalysts are often required for certain applications

Meldrum's Acid in Orgnaic Synthesis

The syntheses and reactions of Meldrum's acid derivatives as well as their applications in natural product syntheses reported during 1978-1990 are reviewed

Domino‐reactions: The tandem‐knoevenagel‐hetero‐diels‐alder reaction and its application in natural product synthesis

Journal of Heterocyclic ChemistryVolume 27, Issue 1 p. 47-69 Article Domino-reactions: The tandem-knoevenagel-hetero-diels-alder reaction and its application in natural product synthesis Lutz F. Tietze, Lutz F. Tietze Institute of Organic Chemistry, Georg-August-Universität, Tammannstraße 2, D-3400 Göttingen, F.R.G.Search for more papers by this author Lutz F. Tietze, Lutz F. Tietze Institute of Organic Chemistry, Georg-August-Universität, Tammannstraße 2, D-3400 Göttingen, F.R.G.Search for more papers by this author First published: January 1990 https://doi.org/10.1002/jhet.5570270105Citations: 190AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume27, Issue1January 1990Pages 47-69 RelatedInformation

The opening of trans-2-3-epoxy-1-butanol derivatives with organometallic reagents

The opening of trans-2-3-epoxy-butan-1-ol derivatives with various organometallic reagents was studied to find the best conditions necessary to obtain convenient yields and regioselectivities for their application in natural product synthesis.

A ring contraction of 6-alkoxy-2,3-dihydro-6h-pyran-3-ones to polyfunctionalized cyclopentenones

The rearrangement of 6-alkoxy-2,3-dihydro-6 H-pyran-3-ones ( 1) to trans-4-alkoxy-5-hydroxy-2-cyclopenten-1-ones ( 2) has been optimized. The effect of buffer concentration (PhCO 2 H/KOAc) on reaction rate and yield suggests specific acid catalysis. Substitution patterns and influence of the 6-alkoxy substituent have been investigated. Applications in natural product synthesis are described.