A5078417346- Synthetic Organic Chemistry Methods
- Cancer Treatment and Pharmacology
- Microbial Natural Products and Biosynthesis
- Chemical synthesis and alkaloids
- Marine Sponges and Natural Products
- Asymmetric Synthesis and Catalysis
- Catalytic C–H Functionalization Methods
- Oxidative Organic Chemistry Reactions
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Chemical Synthesis and Analysis
- Synthesis and Catalytic Reactions
- Asymmetric Hydrogenation and Catalysis
- Advanced Synthetic Organic Chemistry
- Catalytic Cross-Coupling Reactions
- Click Chemistry and Applications
- Computational Drug Discovery Methods
- Peptidase Inhibition and Analysis
- Cyclopropane Reaction Mechanisms
- Alkaloids: synthesis and pharmacology
- Chemical Reaction Mechanisms
- Organic Chemistry Cycloaddition Reactions
- Carbohydrate Chemistry and Synthesis
- Traditional and Medicinal Uses of Annonaceae
- Chemical Reactions and Mechanisms
Princeton University
2015-2024
Chelsea and Westminster Hospital NHS Foundation Trust
2024
Tianjin University
2017-2021
Princeton Public Schools
2016-2018
Flinders University
2015
Technische Universität Berlin
2007
University of California, Los Angeles
2006
Scripps Research Institute
1994-2005
National Institutes of Health
2005
National Cancer Institute
2005
A mild, palladium(II)-catalyzed ring-forming aminoacetoxylation of alkenes is described. Treatment a range nitrogen nucleophiles with catalytic palladium(II) in the presence PhI(OAc)2 as oxidant resulted alkene aminoacetoxylation, affording variety nitrogen-containing heterocycles. Our studies indicate possibility for high levels reaction regio- and stereocontrol. It appears that this stereoselective trans difunctionalization thus useful alternative to related cis-selective, metal-catalyzed...
Abstract The dehydrogenation of unactivated alkanes is an important transformation both in industrial and biological systems. Recent efforts towards this reaction have revolved around high temperature, organometallic C–H activation by noble metal catalysts that produce alkenes hydrogen gas as the sole products. Conversely, natural desaturase systems proceed through stepwise atom transfer at physiological temperature; however, these transformations require a terminal oxidant. Here we show...
Abstract The fluorination of unactivated C(sp 3 )−H bonds remains a desirable and challenging transformation for pharmaceutical, agricultural, materials scientists. Previous methods this have used bench‐stable fluorine atom sources; however, many still rely on the use UV‐active photocatalysts requisite high‐energy hydrogen abstraction event. Uranyl nitrate hexahydrate is described as convenient, catalyst that can mediate fluorinations certain alkanes upon activation with visible light.
Convergent, stereocontrolled total syntheses of the microtubule-stabilizing macrolides epothilones A (2) and B (3) have been achieved. Four distinct ring-forming strategies were pursued (see Scheme 1). Of these four, three reduced to practice. In one approach, action a base on substance possessing an acetate ester nonenolizable aldehyde brought about remarkably effective macroaldolization see (89 → 90 + 91; 99 100 101), simultaneously creating C2−C3 bond hydroxyl-bearing stereocenter at C-3....
An audacious macroaldolization is the key step in first total synthesis of cytotoxic epothilone A, which starts with units 1, 2, and 3. This condensation closes ring to form macrolide, whose structure was determined published (also Angewandte Chemie) as recently July 1996.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTotal Synthesis of taxol. 2. Construction A and C ring intermediates initial attempts to construct the ABC systemK. C. Nicolaou, J.-J. Liu, Z. Yang, H. Ueno, E. J. Sorensen, F. Claiborne, R. K. Guy, C.-K. Hwang, M. Nakada, P. G. NantermetCite this: Am. Chem. Soc. 1995, 117, 2, 634–644Publication Date (Print):January 1, 1995Publication History Published online1 May 2002Published inissue 1 January...
The direct, Pd-catalyzed ortho C-H methylation and fluorination of benzaldehydes have been accomplished using commercially available orthanilic acids as transient directing groups. In these reactions, the 1-fluoro-2,4,6-trimethylpyridinium salts can be either a bystanding F+ oxidant or an electrophilic fluorinating reagent. An X-ray crystal structure benzaldehyde palladation intermediate was obtained triphenylphosphine stabilizing ligand.
The first synthesis of substituted fluorenones directly from benzaldehydes and aryl iodides via a Pd(II)-catalyzed C(sp2)–H functionalization cascade is reported. Featuring anthranilic acid as an inexpensive transient directing group, the process compatible with variety iodides. A three-step antiviral drug Tilorone was completed in excellent overall yield (40%), demonstrating utility this method.
The direct Pd-catalyzed ortho C–H hydroxylation of benzaldehydes was achieved using 4-chloroanthranilic acid as the transient directing group, 1-fluoro-2,4,6-trimethylpyridnium triflate bystanding oxidant, and p-toluenesulfonic putative oxygen nucleophile. unusual chlorination polyfluoroalkoxylation reactions signaled importance external nucleophiles to outcome Pd(IV) reductive eliminations.
Reactions that change the identity of an atom within a ring system are emerging as valuable tools for site-selective editing molecular structures. Herein, we describe expansion underdeveloped transformation directly converts azaarene-derived N-oxides to all-carbon arenes. This transmutation exhibits good functional group tolerance and replaces N-oxide moiety with either unsubstituted, substituted, or isotopically labeled carbon atoms in single laboratory operation.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTotal Synthesis of Taxol. 1. Retrosynthesis, Degradation, and ReconstitutionK. C. Nicolaou, P. G. Nantermet, H. Ueno, R. K. Guy, E. A. Couladouros, J. SorensenCite this: Am. Chem. Soc. 1995, 117, 2, 624–633Publication Date (Print):January 1, 1995Publication History Published online1 May 2002Published inissue 1 January 1995https://pubs.acs.org/doi/10.1021/ja00107a006https://doi.org/10.1021/ja00107a006research-articleACS PublicationsRequest reuse...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTRemote Effects in Macrolide Formation through Ring-Forming Olefin Metathesis: An Application to the Synthesis of Fully Active Epothilone CongenersDongfang Meng, Dai-Shi Su, Aaron Balog, Peter Bertinato, Erik J. Sorensen, Samuel Danishefsky, Yu-Huang Zheng, Ting-Chao Chou, Lifeng He, and Susan B. HorwitzView Author Information Laboratories for Bioorganic Chemistry Biochemical Pharmacology Sloan-Kettering Institute Cancer Research 1275 York...
The highest biological activities displayed by epothilone-related compounds have been found for epothilone B (1) and a derivative that was prepared en route to the natural product. Key steps in total synthesis were Suzuki coupling providing trisubstituted double bond macrocycle its subsequent stereoselective epoxidation with dimethyldioxirane.
The evolution of a strategy culminating in an efficient, enantioselective synthesis the potent microtubule-stabilizing agent FR182877 is described. Guided by proposed biogenesis this complex natural product, solution emerged that involved first reported example double transannular Diels−Alder reaction to fashion key elements its hexacyclic structure. This pivotal transformation creates pentacycle from 19-membered macrocyclic pentaene, forming seven new stereogenic centers fully...
Previous studies on the drug content of pelleted tubulin polymers suggest that peloruside A binds in laulimalide site, which is distinct from taxoid site. In a assembly system containing microtubule-associated proteins and GTP, however, was significantly less active than laulimalide, inducing manner most similar to sarcodictyins B. Because thus far seems be only compound mimics action we examined combinations microtubule-stabilizing agents for synergistic effects assembly. We found showed no...
A rhodium-catalyzed alkyne cyclotrimerization, domino electrocyclic reactions, and a hydroxy-directed dihydroxylation are key steps in an efficient synthesis of the bioactive furanosteroid viridin (1) from simple acyclic triyne.