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Leo A. Paquette

Other affiliations: Heidelberg University
Bio: Leo A. Paquette is an academic researcher from Ohio State University. The author has contributed to research in topics: Ring (chemistry) & Total synthesis. The author has an hindex of 36, co-authored 484 publications receiving 6021 citations. Previous affiliations of Leo A. Paquette include Heidelberg University.


Papers
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Journal ArticleDOI
TL;DR: In this article, an improved preparation of 2-methylene-1,3-dithiolane was shown to undergo inverse-electron-demand Diels-Alder cycloaddition to tropone.
Abstract: Following an improved preparation of 2-methylene-1,3-dithiolane, this ketene acetal was shown to undergo inverse-electron-demand Diels-Alder cycloaddition to tropone. Regiocontrolled copper hydride reduction and resolution via sulfoximine adducts was readily achieved to give (-)-(9). Addition to (9) of the chiral nonracemic vinyl bromides (21) and (22) proceeded with endo capture of the nucleophilic vinyllithium to give carbinols that underwent anionic oxy-Cope rearrangement at somewhat elevated temperatures. The [3,3] sigmatropic event delivered cis,syn, cis-tricyclo[9.3.0.0 2,8 ]tetradecenones possessing structural frame- works related to the cyathins. Once (31) was in hand, it proved an easy matter to introduce added unsaturation and oxygen substituents. The tendency of certain derivatives for transannular cyclization was made quite apparent. Attempts to introduce a C(6)-α-methyl substituent was not achieved, chiefly as the result of the overall molecular concavity of this class of intermediates. A variety of reactions aimed at enhen- cing the level of functionality in rings B and C was explored and processes conducive to the attainment of these goals were developed

3 citations

Book ChapterDOI
TL;DR: The de novo acquisition of taxusin and taxol has been fueled in large part by the enchanted structural features of these molecules and the much heralded antitumor efficacy of 2, particularly in patients beset with refractory ovarian, breast, and lung cancers.
Abstract: Our involvement with the de novo acquisition of taxusin (1) and taxol (2) has been fueled in large part by the enchanting structural features of these molecules and the much heralded antitumor efficacy of 2, particularly in patients beset with refractory ovarian, breast, and lung cancers.1 In combination with the unusual mode of action of 2, which exhibits a remarkable capacity for stabilizing microtubule assembly and deterring cell division,2 the intrinsically exciting promise shown by taxol for benefiting human health has commanded unrivaled attention.

2 citations

Journal ArticleDOI
TL;DR: The odoriferous principle of black tea has been produced from 2,2-dimethylcyclopentanone as discussed by the authors, where the reaction sequence begins with 1, 2-addition of 5-lithio-2-methyl-2,3-dihydrofuran to this ketone and immediate acid-catalyzed ring expansion of the resulting carbinols to a separable pair of spiro ethers.
Abstract: The odoriferous principle of black tea has been produced from 2,2-dimethylcyclopentanone. The reaction sequence begins with 1,2-addition of 5-lithio-2-methyl-2,3-dihydrofuran to this ketone and immediate acid-catalyzed ring expansion of the resulting carbinols to a separable pair of spiro ethers. Individual conversion of these diastereomers to α,β-unsaturated ketones is followed by tandem condensation with the methyllithium−lithium bromide complex and oxidation with pyridinium chlorochromate.

2 citations

Journal ArticleDOI
TL;DR: In this article, an enantioselective approach to 2'deoxy-4'thia spirocyclic nucleosides featuring an α- or β-hydroxyl substituent at C-5' of the carbocyclic ring is described.
Abstract: An enantioselective approach to 2‘-deoxy-4‘-thia spirocyclic nucleosides featuring an α- or β-hydroxyl substituent at C-5‘ of the carbocyclic ring is detailed. The starting point is the mandelate a...

2 citations


Cited by
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Journal ArticleDOI
TL;DR: This review covers the literature published in 2014 for marine natural products, with 1116 citations referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms.

4,649 citations

Journal ArticleDOI
TL;DR: This Review provides an overview of C-H bond functionalization strategies for the rapid synthesis of biologically active compounds such as natural products and pharmaceutical targets.
Abstract: The direct functionalization of C-H bonds in organic compounds has recently emerged as a powerful and ideal method for the formation of carbon-carbon and carbon-heteroatom bonds. This Review provides an overview of C-H bond functionalization strategies for the rapid synthesis of biologically active compounds such as natural products and pharmaceutical targets.

2,391 citations

Journal ArticleDOI
TL;DR: In this Review, highlights of a number of selected syntheses are discussed, demonstrating the enormous power of these processes in the art of total synthesis and underscore their future potential in chemical synthesis.
Abstract: In studying the evolution of organic chemistry and grasping its essence, one comes quickly to the conclusion that no other type of reaction plays as large a role in shaping this domain of science than carbon-carbon bond-forming reactions. The Grignard, Diels-Alder, and Wittig reactions are but three prominent examples of such processes, and are among those which have undeniably exercised decisive roles in the last century in the emergence of chemical synthesis as we know it today. In the last quarter of the 20th century, a new family of carbon-carbon bond-forming reactions based on transition-metal catalysts evolved as powerful tools in synthesis. Among them, the palladium-catalyzed cross-coupling reactions are the most prominent. In this Review, highlights of a number of selected syntheses are discussed. The examples chosen demonstrate the enormous power of these processes in the art of total synthesis and underscore their future potential in chemical synthesis.

2,268 citations

Journal ArticleDOI
Chao-Jun Li1
TL;DR: Reaction of R,â-Unsaturated Carbonyl Compounds 3127: Reaction of R-UnSaturated Carbonies 3127 7.1.6.
Abstract: 4.2.8. Reductive Coupling 3109 5. Reaction of Aromatic Compounds 3110 5.1. Electrophilic Substitutions 3110 5.2. Radical Substitution 3111 5.3. Oxidative Coupling 3111 5.4. Photochemical Reactions 3111 6. Reaction of Carbonyl Compounds 3111 6.1. Nucleophilic Additions 3111 6.1.1. Allylation 3111 6.1.2. Propargylation 3120 6.1.3. Benzylation 3121 6.1.4. Arylation/Vinylation 3121 6.1.5. Alkynylation 3121 6.1.6. Alkylation 3121 6.1.7. Reformatsky-Type Reaction 3122 6.1.8. Direct Aldol Reaction 3122 6.1.9. Mukaiyama Aldol Reaction 3124 6.1.10. Hydrogen Cyanide Addition 3125 6.2. Pinacol Coupling 3126 6.3. Wittig Reactions 3126 7. Reaction of R,â-Unsaturated Carbonyl Compounds 3127

2,031 citations

Journal ArticleDOI
TL;DR: The power of cascade reactions in total synthesis is illustrated in the construction of complex molecules and underscore their future potential in chemical synthesis.
Abstract: The design and implementation of cascade reactions is a challenging facet of organic chemistry, yet one that can impart striking novelty, elegance, and efficiency to synthetic strategies. The application of cascade reactions to natural products synthesis represents a particularly demanding task, but the results can be both stunning and instructive. This Review highlights selected examples of cascade reactions in total synthesis, with particular emphasis on recent applications therein. The examples discussed herein illustrate the power of these processes in the construction of complex molecules and underscore their future potential in chemical synthesis.

1,762 citations