Toward the total synthesis of lophotoxin — New methodologies and synthetic strategies

2006 ◽  
Vol 84 (10) ◽  
pp. 1226-1241 ◽  
Author(s):  
Peter Wipf ◽  
Michel Grenon
Keyword(s):  
Transition Metal ◽  
Total Synthesis ◽  
Recent Progress ◽  
Furan Ring ◽  
Addition Reaction ◽  
Thermal Conditions ◽  
Preliminary Results ◽  
Keto Esters ◽  
New Methodologies ◽  
Metal Catalyzed

Our recent progress toward the synthesis of the furanocembranolide lophotoxin (1) is disclosed. Strategies for the stereoselective incorporation of the C13 stereocenter by a catalytic desymmetrization of a cyclic meso-anhydride, as well as a novel 1,6-addition reaction of organocuprates to unsaturated [1,3]dioxin-4-ones are discussed. Preliminary results on the development of a rhodium-catalyzed asymmetric 1,6-addition reaction are also mentioned. Finally, modifications of a previously reported transition-metal-catalyzed cyclization reaction involving α-propargyl β-keto esters allow furan ring formation either under thermal conditions or by microwave irradiation.Key words: 1,6-addition, organocuprates, catalytic desymmetrization, furan cyclization, microwave.

scholarly journals New cyclization reactions in organic syntheses

2002 ◽  
Vol 74 (1) ◽  
pp. 159-166 ◽  
Author(s):  
Iwao Ojima
Keyword(s):  
Amino Acids ◽  
Transition Metal ◽  
Total Synthesis ◽  
Cyclization Reactions ◽  
Organic Syntheses ◽  
Carbocyclic Compounds ◽  
Efficient Construction ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

Recent development in the transition metal-catalyzed cyclization reactions for organic syntheses in the author's laboratories is summarized, which includes (i) novel silylcarbocyclizations (SiCaCs) and carbonylative carbotricyclizations, (ii) intramolecular silylformylations and desymmerization of siloxydiynes by sequential double silylformylation, (iii) efficient total synthesis of (+)-prosopinine, (iv) enantioselective desymmetrization of aminodienes, and (iv) new and efficient routes to 1-azabicyclo[x.y.0]alkane amino acids. All these processes are catalyzed by Rh or Rh­Co complexes, and useful for rapid and efficient construction of a variety of heterocyclic and carbocyclic compounds. Mechanisms of these new carbocyclization and cyclohydrocarbonylation reactions are also discussed.

Transition-Metal-Catalyzed Reactions Involving Arynes

Synthesis ◽  
2017 ◽  
Vol 50 (01) ◽  
pp. 1-16 ◽  
Author(s):  
Santosh Mhaske ◽  
Ranjeet Dhokale
Keyword(s):  
Natural Products ◽  
Transition Metal ◽  
Total Synthesis ◽  
Scientific Community ◽  
Multicomponent Reactions ◽  
Polycyclic Aromatic Compounds ◽  
Polycyclic Aromatic ◽  
Transition Metal Catalyzed ◽  
Catalyzed Reactions ◽  
Metal Catalyzed

The plethora of transformations attainable by the transition-metal-catalyzed reactions of arynes has found immense contemporary interest in the scientific community. This review highlights the scope and importance of transition-metal-catalyzed aryne reactions in the field of synthetic organic chemistry reported to date. It covers transformations achieved by the combination of arynes and various transition metals, which provide a facile access to a biaryl motif, fused polycyclic aromatic compounds, different novel carbocycles, various heterocycles, and complex natural products.1 Introduction2 Insertion of Arynes3 Annulation of Arynes4 Cycloaddition of Arynes5 Multicomponent Reactions of Arynes6 Miscellaneous Reactions of Arynes7 Total Synthesis of Natural Products Using Arynes8 Conclusion

scholarly journals Transition metal catalyzed stereodivergent synthesis of syn- and anti-δ-vinyl-lactams: formal total synthesis of (−)-cermizine C and (−)-senepodine G

2019 ◽  
Vol 10 (10) ◽  
pp. 3074-3079 ◽  
Author(s):  
Johannes Philipp Schmidt ◽  
Bernhard Breit
Keyword(s):  
Transition Metal ◽  
Total Synthesis ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

A stereodivergent and diastereoselective transition-metal-catalyzed intramolecular hydroamidation of allenes and alkynes furnishing δ-vinyl-lactams is reported.

scholarly journals Synthesis of Polyhedral Borane Cluster Fused Heterocycles via Transition Metal Catalyzed B-H Activation

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 391 ◽  
Author(s):  
Ke Cao ◽  
Cai-Yan Zhang ◽  
Tao-Tao Xu ◽  
Ji Wu ◽  
Xin-Yu Wen ◽  
...  
Keyword(s):  
Transition Metal ◽  
Recent Progress ◽  
Building Blocks ◽  
Bioactive Natural Products ◽  
Fused Heterocycles ◽  
Selective Functionalization ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed ◽  
Photoluminescent Materials ◽  
Borane Cluster

Aromatic heterocycles are ubiquitous building blocks in bioactive natural products, pharmaceutical and agrochemical industries. Accordingly, the carborane-fused heterocycles would be potential candidates in drug discovery, nanomaterials, metallacarboranes, as well as photoluminescent materials. In recent years, the transition metal catalyzed B-H activation has been proved to be an effective protocol for selective functionalization of B-H bond of o-carboranes, which has been further extended for the synthesis of polyhedral borane cluster-fused heterocycles via cascade B-H functionalization/annulation process. This article summarizes the recent progress in construction of polyhedral borane cluster-fused heterocycles via B-H activation.

Recent progress in transition-metal-catalyzed hydrocyanation of nonpolar alkenes and alkynes

2020 ◽  
Vol 18 (3) ◽  
pp. 391-399 ◽  
Author(s):  
Hongru Zhang ◽  
Xin Su ◽  
Kaiwu Dong
Keyword(s):  
Transition Metal ◽  
Recent Progress ◽  
Building Blocks ◽  
Powerful Method ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

Hydrocyanation is a powerful method for the preparation of nitriles which are versatile building blocks for the synthesis of amines, acids and amides.

Rhodium-Catalyzed Synthesis of Organosulfur Compounds using Sulfur

Synlett ◽  
2019 ◽  
Vol 30 (14) ◽  
pp. 1621-1631
Author(s):  
Mieko Arisawa ◽  
Masahiko Yamaguchi
Keyword(s):  
Transition Metal ◽  
Sulfur Atom ◽  
Addition Reaction ◽  
Transition Metal Catalysts ◽  
Organosulfur Compounds ◽  
Exchange Reactions ◽  
Sulfur Addition ◽  
Catalyzed Reactions ◽  
Metal Catalyzed ◽  
Natural Amino Acids

Sulfur is one of the few elements that occurs uncombined in nature. Sulfur atoms are found in natural amino acids and vitamins. In the chemical industry, organosulfur compounds are used for fabricating rubber, fibers, and dyes, pharmaceuticals, and pesticides. Although sulfur, which is cheap and easy to handle, is a useful source of sulfur atom in functional organosulfur compounds, it is rarely used in organic synthesis. Activation of sulfur by high temperature, light irradiation, treatment with nucleophiles and electrophiles, and redox conditions often results in the formation of various active sulfur species, which complicate reactions. The development of a method that mildly activates sulfur is therefore desired. The use of transition-metal catalysts is a new method of activating sulfur under mild conditions, and, in this article, we describe the rhodium-catalyzed synthesis of various organosulfur compounds by the insertion of sulfur atoms into single bonds and by the addition of sulfur to unsaturated bond in various organic compounds.1 Introduction2 Sulfur Activation without using Transition Metal3 Transition-Metal-Catalyzed Activation of Sulfur4 Rhodium-Catalyzed Reactions using Sulfur4.1 Rhodium-Catalyzed Sulfur Atom Exchange Reactions using Sulfur4.2 Synthesis of Diaryl Sulfides using Rhodium-Catalyzed Exchange Reaction of Aryl Fluorides and Sulfur/Organopolysulfides4.3 Rhodium-Catalyzed Synthesis of Isothiocyanate using Sulfur4.4 Rhodium-Catalyzed Sulfur Addition Reaction to Alkenes for Thiiranes Synthesis4.5 Rhodium-Catalyzed Sulfur Addition Reaction to Alkynes for 1,4-Dithiins Synthesis5 Conclusion

Chromium-Catalyzed Cross-Couplings and Related Reactions

Synthesis ◽  
2019 ◽  
Vol 51 (10) ◽  
pp. 2100-2106 ◽  
Author(s):  
Jie Li ◽  
Paul Knochel
Keyword(s):  
Transition Metal ◽  
Recent Progress ◽  
Short Review ◽  
High Price ◽  
Nickel Catalysis ◽  
Catalytic Reactivity ◽  
Transition Metal Catalyzed ◽  
Low Valent ◽  
Metal Catalyzed ◽  
Remarkable Progress

Transition-metal-catalyzed cross-couplings have been recognized as a powerful tool for sustainable syntheses. Despite the fact that remarkable progress was achieved by palladium and nickel catalysis, the high price and toxicity still remained a drawback. Recently, naturally more abundant and less toxic low-valent chromium salts, such as Cr(II) and Cr(III) chlorides, displayed notable unique catalytic reactivity. Thus, recent progress in the field of chromium-catalyzed cross-couplings and related reactions are highlighted in the present short review until December­ 2018.1 Introduction and Early Chromium-Mediated Reactions2 Chromium-Catalyzed Cross-Couplings and Related Reactions3 Conclusion

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