Development of a Hydrazine-Catalyzed Carbonyl-Olefin Metathesis Reaction

Synlett ◽  
2019 ◽  
Vol 30 (17) ◽  
pp. 1954-1965 ◽  
Author(s):  
Tristan H. Lambert
Keyword(s):  
Double Bond ◽  
Organic Synthesis ◽  
Olefin Metathesis ◽  
Type I ◽  
Type Ii ◽  
Metathesis Reaction ◽  
Alternative Strategies ◽  
Potential Applications ◽  
Acid Catalyzed ◽  
New Strategies

Carbonyl-olefin metathesis is a potentially powerful yet underexplored reaction in organic synthesis. In recent years, however, this situation has begun to change, most notably with the introduction of several different catalytic technologies. The development of one of those new strategies, based on hydrazine catalysts and a novel [3+2] paradigm for double bond metathesis, is discussed herein. First, the stage is set with a description of some potential applications of carbonyl-olefin metathesis and a discussion of alternative strategies for this intriguing reaction.1 Introduction2 Potential Applications of Carbonyl-Olefin Metathesis3 Carbonyl-Olefin Metathesis Strategies4 Direct (Type I): Non-Catalytic5 Direct (Type I): Acid-Catalyzed6 Indirect (Type II): Metal Alkylidenes7 Indirect (Type III): Hydrazine-Catalyzed8 Conclusion

Stereodivergent synthesis of 1,4-dicarbonyls by traceless charge–accelerated sulfonium rearrangement

Science ◽  
2018 ◽  
Vol 361 (6403) ◽  
pp. 664-667 ◽  
Author(s):  
Dainis Kaldre ◽  
Immo Klose ◽  
Nuno Maulide
Keyword(s):  
Natural Products ◽  
Double Bond ◽  
Carbonyl Group ◽  
Organic Synthesis ◽  
Relative Configuration ◽  
Chiral Induction ◽  
Tremendous Importance ◽  
Acid Catalyzed ◽  
Quaternary Stereocenters ◽  
Drug Scaffolds

The chemistry of the carbonyl group is essential to modern organic synthesis. The preparation of substituted, enantioenriched 1,3- or 1,5-dicarbonyls is well developed, as their disconnection naturally follows from the intrinsic polarity of the carbonyl group. By contrast, a general enantioselective access to quaternary stereocenters in acyclic 1,4-dicarbonyl systems remains an unresolved problem, despite the tremendous importance of 2,3-substituted 1,4-dicarbonyl motifs in natural products and drug scaffolds. Here we present a broad enantioselective and stereodivergent strategy to access acyclic, polysubstituted 1,4-dicarbonyls via acid-catalyzed [3,3]-sulfonium rearrangement starting from vinyl sulfoxides and ynamides. The stereochemistry at sulfur governs the absolute sense of chiral induction, whereas the double bond geometry dictates the relative configuration of the final products.

scholarly journals Iodonium-Catalyzed Carbonyl–Olefin Metathesis Reactions

Synlett ◽  
2019 ◽  
Vol 30 (17) ◽  
pp. 1966-1970 ◽  
Author(s):  
Giulia Oss ◽  
Thanh Vinh Nguyen
Keyword(s):  
Transition Metal ◽  
Organic Compounds ◽  
Organic Synthesis ◽  
Olefin Metathesis ◽  
Lewis Acids ◽  
Functional Group ◽  
Iodine Monochloride ◽  
Metathesis Reaction ◽  
Reaction Conditions ◽  
Recent Developments

The carbonyl–olefin metathesis reaction has become increasingly important in organic synthesis due to its versatility in functional group interconversion chemistry. Recent developments in the field have identified a number of transition-metal and organic Lewis acids as effective catalysts for this reaction. Herein, we report the use of simple organic compounds such as N-iodosuccinimide or iodine monochloride to catalyze the carbonyl–olefin metathesis process under mild reaction conditions. This work broadens the scope of this chemical transformation to include iodonium sources as simple and practical catalysts.

scholarly journals Aqueous olefin metathesis: recent developments and applications

2019 ◽  
Vol 15 ◽  
pp. 445-468 ◽  
Author(s):  
Valerio Sabatino ◽  
Thomas R Ward
Keyword(s):  
Double Bond ◽  
Organic Synthesis ◽  
Olefin Metathesis ◽  
Chemical Biology ◽  
Polymer Chemistry ◽  
Attractive Alternative ◽  
Bond Forming ◽  
Recent Developments ◽  
Tremendous Impact ◽  
Made In

Olefin metathesis is one of the most powerful C–C double-bond-forming reactions. Metathesis reactions have had a tremendous impact in organic synthesis, enabling a variety of applications in polymer chemistry, drug discovery and chemical biology. Although challenging, the possibility to perform aqueous metatheses has become an attractive alternative, not only because water is a more sustainable medium, but also to exploit biocompatible conditions. This review focuses on the progress made in aqueous olefin metatheses and their applications in chemical biology.

Connecting catalytic cycles by organometallic transformations in situ: Novel perspectives in the olefin metathesis field

2006 ◽  
Vol 78 (2) ◽  
pp. 469-476 ◽  
Author(s):  
Bernd Schmidt
Keyword(s):  
Double Bond ◽  
Olefin Metathesis ◽  
Metathesis Reaction ◽  
Ring Closing Metathesis ◽  
Double Bond Isomerization ◽  
Metathesis Catalyst ◽  
Organometallic Transformations ◽  
Catalytic Cycles

Tandem sequences consisting of an olefin metathesis step and a subsequent non-metathesis reaction become accessible by organometallic transformations of the Ru-carbene species in situ. This contribution highlights some tandem sequences that rely on the conversion of the metathesis catalyst to Ru-hydrides, with special emphasis on the tandem ring-closing metathesis (RCM)-double-bond isomerization sequence.

Domino Reactions of Tertiary Enamides in Organic Synthesis

Synlett ◽  
2021 ◽  
Author(s):  
Shuo Tong ◽  
Mei-Xiang Wang
Keyword(s):  
Organic Synthesis ◽  
Recent Decade ◽  
Type I ◽  
Type Ii ◽  
Domino Reactions ◽  
Type Iii ◽  
Nucleophilic Reactions ◽  
Shelf Stable

AbstractStudies in recent decade have shown that tertiary enamides, once thought of as unreactive and marginally useful enamine variants, are shelf-stable yet versatile nucleophilic intermediates in organic synthesis. Many compounds, especially N-heterocycles, have been synthesized by monofunctionalization reactions of tertiary enamides. By taking advantage of intramolecular and intermolecular interception of the putative acyliminium intermediates formed by the initial nucleophilic reactions of tertiary enamides, we have established several novel difunctionalization reaction methods for constructing diverse complex fused heterocyclic products. In this Account, we summarize our endeavors to develop difunctionalization reactions of tertiary enamides in a domino fashion.1 Introduction2 Strategic Considerations3 Domino Reactions of Tertiary Enamides3.1 Type I Domino Reactions3.2 Type II Domino Reactions3.3 Type III Domino Reactions4 Conclusion and Perspectives

Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

1970 ◽  
Vol 28 ◽  
pp. 106-107 ◽  
Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt
Keyword(s):  
New Zealand ◽  
General Hospital ◽  
Massachusetts General Hospital ◽  
Type I ◽  
Type Ii ◽  
Collaborative Effort ◽  
Temperature And Pressure ◽  
The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

Labelling of non-A, non-B hepatitis infected chimpanzee hepatocytes with nuclease-gold conjugates

1984 ◽  
Vol 42 ◽  
pp. 250-251
Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson
Keyword(s):  
Endoplasmic Reticulum ◽  
Experimental Infection ◽  
Uranyl Acetate ◽  
Type I ◽  
Cellular Injury ◽  
Type Ii ◽  
Tubular Structures ◽  
Type Iii ◽  
Type Iv ◽  
Infected Chimpanzee

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.

Comparative surface and ultrastructural views of methylotrophic bacteria by TEM, STEM, SE, and freeze-etch electron microscopy.

1987 ◽  
Vol 45 ◽  
pp. 792-793
Author(s):  
T.A. Fassel ◽  
M.J. Schaller ◽  
M.E. Lidstrom ◽  
C.C. Remsen
Keyword(s):  
Cytoplasmic Membrane ◽  
Structural Features ◽  
Methylotrophic Bacteria ◽  
Type I ◽  
Type Ii ◽  
Membrane Complex ◽  
Oxidation Of Methane ◽  
Methane Oxidizing Bacteria ◽  
Wall Structures ◽  
Methylomonas Albus

Methylotrophic bacteria play an Important role in the environment in the oxidation of methane and methanol. Extensive intracytoplasmic membranes (ICM) have been associated with the oxidation processes in methylotrophs and chemolithotrophic bacteria. Classification on the basis of ICM arrangement distinguishes 2 types of methylotrophs. Bundles or vesicular stacks of ICM located away from the cytoplasmic membrane and extending into the cytoplasm are present in Type I methylotrophs. In Type II methylotrophs, the ICM form pairs of peripheral membranes located parallel to the cytoplasmic membrane. Complex cell wall structures of tightly packed cup-shaped subunits have been described in strains of marine and freshwater phototrophic sulfur bacteria and several strains of methane oxidizing bacteria. We examined the ultrastructure of the methylotrophs with particular view of the ICM and surface structural features, between representatives of the Type I Methylomonas albus (BG8), and Type II Methylosinus trichosporium (OB-36).

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