3.7. Palladium Nanoparticles as Catalysts 888 3.8. Other Transition-Metal Complexes 888 3.9. Transition-Metal-Free Reactions 889 4. Applications 889 4.1. Alkynylation of Arenes 889 4.2. Alkynylation of Heterocycles 891 4.3. Synthesis of Enynes and Enediynes 894 4.4. Synthesis of Ynones 896 4.5. Synthesis of Carbocyclic Systems 897 4.6. Synthesis of Heterocyclic Systems 898 4.7. Synthesis of Natural Products 903 4.8. Synthesis of Electronic and Electrooptical Molecules 906

https://www.chem.ccu.edu.tw/~joyce/referance/ericyang/Chem.%20Rev/Chem.%20Rev.%202007,%20107,%20874-922.pdf

The Sonogashira Reaction: A Booming Methodology in Synthetic Organic Chemistry†

Palladium-catalyzed alkynylation.

The [2 + 2] photocycloaddition is undisputedly the most important and most frequently used photochemical reaction. In this review, it is attempted to cover all recent aspects of [2 + 2] photocycloaddition chemistry with an emphasis on synthetically relevant, regio-, and stereoselective reactions. The review aims to comprehensively discuss relevant work, which was done in the field in the last 20 years (i.e., from 1995 to 2015). Organization of the data follows a subdivision according to mechanism and substrate classes. Cu(I) and PET (photoinduced electron transfer) catalysis are treated separately in sections 2 and 4, whereas the vast majority of photocycloaddition reactions which occur by direct excitation or sensitization are divided within section 3 into individual subsections according to the photochemically excited olefin.

http://pubs.acs.org/doi/pdf/10.1021/acs.chemrev.5b00723

Recent Advances in the Synthesis of Cyclobutanes by Olefin [2+2] Photocycloaddition Reactions

This paper reviews the tools to manipulate and minimize the band gap of conjugated (co)polymers. The effects of minimization of the bond length alternation and of the incorporation of donor-π-acceptor units are discussed in particular. A systematic study of a series of alternating donor–acceptor oligomers has revealed the achievable limits and allowed for a prognosis of the performance of corresponding copolymers. The decisive influence of the LUMO eigenvectors of the acceptors on the band gap is highlighted. A new synthesis of benzo[1,2-c:4,5-c]bis[1,2,5]thiadiazole containing donor–acceptor monomers and their acid-catalyzed polymerization are described. Finally, band gap tuning by appropriate substitution, conformational adjustment and mesoscopic ordering is discussed.

Developments in the chemistry and band gap engineering of donor-acceptor substituted conjugated polymers

Stereocontrolled synthesis of tetrasubstituted olefins.

Irradiation (λ > 340 nm) of the title compound 2a in t-BuOH affords 3,3,10,10-tetramethyl-2,8-dioxatricyclo-[4.3.2.01,6]undecane-5,9-dione (3)via photoextrusion of 2-methylpropene and subsequent photocycloaddition of 2a to the alkene. The same regioisomer 3 is formed selectively and in much higher yields on irradiating 2a in the presence of excess 2-methylpropene. Irradiation of 3 (λ = 300 nm) in t-BuOH in the presence of the same alkene gives a 6:1 mixture of spirooxetanes 7a and 7b but not α-cleavage products. In 2-propanol, 2a is photoreduced to a 2:1 mixture of diastereoisomeric hydrodimers 9.

Photochemistry of 2,2-dimethyl-2H-furo[3,4-b]pyran-4,7(3H,5H)-dione

On irradiation (λ=300 nm),2,2,6,6-tetramethylcyclohex-3-enone (1) is cleanly converted into1-(2,2-dimethylcyclopropyl)-2-methylpropene (3); similarly,6-oxo-1,5,5-trimethylcyclohex-2-ene-1-carbonitrile (2) affords amixture of (Z
)- and(E
)-3-(2,2-dimethylcyclopropyl)-2-methylpropenonitriles4a and 4b.

Photodecarbonylation of 2,2,6,6-TetrasubstitutedCyclohex-3-enones to Vinylcyclopropanes†

Exploring the 1,5 Cyclization of Alkyl Propargyl 1,4 Biradicals

Synthese de la [dimethyl-4',4' fluoro-2' cyclohexadiene-1',5' yl]-1 piperidine et de la [dimethyl-4',4' fluoro-2' cyclohexadiene-1',5' yl]-1 morpholine a partir de la dimethyl-4,4 fluoro-6 cyclohexene-2 one Ces produits reagissent avec l'acrylate de methyle pour donner des bicyclo [222] octanes substitues

Synthesis of 1‐Fluoro‐2‐amino‐1,3‐cyclohexadienes and 1‐Fluorobicyclo[2.2.2]octan‐2‐ones

Irradiation (λ = 254 nm) of N-(4,4,6,6-tetramethyl-2-cyclohexen-1-ylidene)-1,1,3,3-tetramethyl-2-cyclohexen-1-ylidene-1,1,3,3-tetramethylbutylamine (7d), which in turn is photodecomposed by light of the same wavelength, but at a four times slower rate than it is formed The rate of formation of photoproduct 7d is a function of the concentration of starting material 1d, suggesting the involvement of a bimolecular (1d* + 1d) step The structure of 7d was established by spectroscopy and by its hydrolysis to 3-cyclohexyl-4,4,6,6-tetramethyl-2-cyclohexenone (8) The previously made assumption that N-(2-cyclohexen-1-ylidene)cyclohexylamine (1a) and 2,3,4,4a,5,6-hexahydroquinolines 2 photorearrange to N-cyclohexylidenecyclohexanamine 3a and 3,4,4a,5,6,8a-hexahydroquinolines 4, respectively, via a light-induced 1,3-hydrogen shift proves incorrect

Paul Margaretha

Papers

Photochemistry of 2,2-dimethyl-2H-furo[3,4-b]pyran-4,7(3H,5H)-dione

Photodecarbonylation of 2,2,6,6-TetrasubstitutedCyclohex-3-enones to Vinylcyclopropanes†

Exploring the 1,5 Cyclization of Alkyl Propargyl 1,4 Biradicals

Synthesis of 1‐Fluoro‐2‐amino‐1,3‐cyclohexadienes and 1‐Fluorobicyclo[2.2.2]octan‐2‐ones

Photochemistry of N-(2-cyclohexen-1-ylidene)alkylamines