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

Organic Reactions in Aqueous Media with a Focus on Carbon−Carbon Bond Formations: A Decade Update

Chamomile (Matricaria recutita L., Chamomilla recutita L., Matricaria chamomilla) is one of the most popular single ingredient herbal teas, or tisanes. Chamomile tea, brewed from dried flower heads, has been used traditionally for medicinal purposes. Evidence-based information regarding the bioactivity of this herb is presented. The main constituents of the flowers include several phenolic compounds, primarily the flavonoids apigenin, quercetin, patuletin, luteolin and their glucosides. The principal components of the essential oil extracted from the flowers are the terpenoids alpha-bisabolol and its oxides and azulenes, including chamazulene. Chamomile has moderate antioxidant and antimicrobial activities, and significant antiplatelet activity in vitro. Animal model studies indicate potent antiinflammatory action, some antimutagenic and cholesterol-lowering activities, as well as antispasmotic and anxiolytic effects. However, human studies are limited, and clinical trials examining the purported sedative properties of chamomile tea are absent. Adverse reactions to chamomile, consumed as a tisane or applied topically, have been reported among those with allergies to other plants in the daisy family, i.e. Asteraceae or Compositae.

A Review of the bioactivity and potential health benefits of chamomile tea (Matricaria recutita L.)

Orbital Symmetries and endo-exo Relationships in Concerted Cycloaddition Reaction (福井謙一とフロンティア軌導理論) -- (参考論文)

Cyclic sulfides in organic synthesis

Organic reactions using water as solvent are reviewed with a focus on pericyclic reactions, carbonyl additions, stoichiometric organometallic reactions, oxidations and reductions which show an unusual outcome in terms of reactivity and selectivity compared with those performed in organic solvent. The advantages of using water as a solvent are discussed and related to the hydrophobic effects and the hydrogen-bonding ability of water with a special emphasis on its very high cohesive energy density which strongly favors organic reactions having a negative activation volume.

Water as Solvent in Organic Synthesis

The Diels–Alder reactions between isoprene and N-phenylmaleimide catalysed by Lewis acids, in particular by aluminium chloride and by lithium perchlorate, have volumes of activation more negative than does the uncatalysed reaction. That between anthracene-9-methanol and N-ethyl-maleimide is faster in water than in organic solvents, and has a slightly more negative volume of activation in the aqueous than in the organic medium. The significance of these measurements is discussed.

Volumes of activation for catalysed Diels–Alder reactions

The volume profile for a cheletropic reaction

Rates of addition of sulphur dioxide to some 1,3-dienes

This paper describes the kinetics and mechanism of oxidation of several monohydric alcohols to the corresponding aldehydes and ketones by bis(quinuclidine)bromine(I) bromide in the presence of pyridinium trifluoroacetate. All evidence from the thermodynamic parameters, deuterium kinetic isotope effect, and Hammett reaction constants supports a two-step mechanism and suggests that the transfer of hydride ion from the substrate to the oxidant is the rate-determining step.

Kinetics and mechanism of oxidation of alcohols

Rates of decomposition of 18 substituted dihydrothiophen 1, 1-dioxides in solution (to yield the corresponding butadiene and SO2) are reported, together with activation parameters and solvent and isotope effects. Rates are mildly accelerated by +M groups at C-3 and by alkyl substituents at C-2 but sterically retarded by bulky groups at C-3 and especially by two β-substituents. 3, 4, 5, 6-Tetrahydro-1H-cyclopenta[c]thiophen 2, 2-dioxide is especially reactive and this is attributed to strain release during fragmentation. The reactions accord in general with requirements for a chelotropic reaction.

Abdulhameed Laila

Papers

Volumes of activation for catalysed Diels–Alder reactions

The volume profile for a cheletropic reaction

Rates of addition of sulphur dioxide to some 1,3-dienes

Kinetics and mechanism of oxidation of alcohols

Reaction of 1,3-dienes with sulphur dioxide. Part 1. Thermal decomposition of 2,5-dihydrothiophen 1,1-dioxides