ChemInform Abstract: Role of Copper in Catalyzing Aryl and Heteroaryl-Nitrogen (or -Oxygen) Bond Formation under Ligand-Free and Solvent-Free Conditions.

ChemInform ◽  
2009 ◽  
Vol 40 (10) ◽  
Author(s):  
Basudeb Basu ◽  
Sajal Das ◽  
Bablee Mandal
Keyword(s):  
Bond Formation ◽  
Solvent Free ◽  
Solvent Free Conditions ◽  
Ligand Free ◽  
Oxygen Bond

Solvent-Free Carbon—Oxygen Bond Formation Catalyzed by CeCl3×7H2O/NaI: Tetrahydropyranylation of Hydroxy Groups.

ChemInform ◽  
2006 ◽  
Vol 37 (27) ◽  
Author(s):  
Giuseppe Bartoli ◽  
Riccardo Giovannini ◽  
Arianna Giuliani ◽  
Enrico Marcantoni ◽  
Massimo Massaccesi ◽  
...  
Keyword(s):  
Bond Formation ◽  
Free Carbon ◽  
Solvent Free ◽  
Hydroxy Groups ◽  
Oxygen Bond

scholarly journals The two-step mechanochemical synthesis of porphyrins

2014 ◽  
Vol 170 ◽  
pp. 59-69 ◽  
Author(s):  
Hannah Shy ◽  
Paula Mackin ◽  
Andrea S. Orvieto ◽  
Deepa Gharbharan ◽  
Geneva R. Peterson ◽  
...  
Keyword(s):  
Organic Solvent ◽  
Mechanochemical Synthesis ◽  
Bond Formation ◽  
Acid Catalyst ◽  
Solvent Free ◽  
Oxidizing Agent ◽  
Carbon Bond ◽  
Carbon Carbon Bond ◽  
Solvent Free Conditions ◽  
Porphyrin Synthesis

Porphyrin synthesis under solvent-free conditions represents the “greening” of a traditional synthesis that normally requires large amounts of organic solvent, and has hindered the industrial-scale synthesis of this useful class of molecules. We have found that the four-fold acid-catalysed condensation of aldehyde and pyrrole to yield a tetra-substituted porphyrin is possible through mechanochemical techniques, without a solvent present. This represents one of the still-rare examples of carbon–carbon bond formation by mechanochemistry. Specifically, upon grinding equimolar amounts of pyrrole and benzaldehyde in the presence of an acid catalyst, cyclization takes place to give reduced porphyrin precursors (reversible), which upon oxidation form tetraphenylporphyrin (TPP). The approach has been found to be suitable for the synthesis of a variety of meso-tetrasubstituted porphyrins. Oxidation can occur either by using an oxidizing agent in solution, to give yields comparable to those published for traditional methods of porphyrin synthesis, or through mechanochemical means resulting in a two-step mechanochemical synthesis to give slightly lower yields that are still being optimized. We are also working on “green” methods of porphyrin isolation, including entrainment sublimation, which would hopefully further reduce the need for large amounts of organic solvent. These results hold promise for the development of mechanochemical synthetic protocols for porphyrins and related classes of compounds.

Solvent-Free Carbon–Oxygen Bond Formation Catalysed by CeCl3·7 H2O/NaI: Tetrahydropyranylation of Hydroxy Groups

2006 ◽  
Vol 2006 (6) ◽  
pp. 1476-1482 ◽  
Author(s):  
Giuseppe Bartoli ◽  
Riccardo Giovannini ◽  
Arianna Giuliani ◽  
Enrico Marcantoni ◽  
Massimo Massaccesi ◽  
...  
Keyword(s):  
Bond Formation ◽  
Free Carbon ◽  
Solvent Free ◽  
Hydroxy Groups ◽  
Oxygen Bond

Solvent-free Substitution Reactions of Solid Phosphines with (η5-RC5H4)Fe(CO)2I (R = H, Me) Complexes

2007 ◽  
Vol 62 (3) ◽  
pp. 453-459 ◽  
Author(s):  
Apollinaire Munyaneza ◽  
Muhammad D. Bala ◽  
Neil J. Coville
Keyword(s):  
Benzene Solution ◽  
Phosphine Ligands ◽  
Solvent Free ◽  
Substitution Reactions ◽  
Ionic Complex ◽  
Solvent Free Conditions ◽  
Mechanism Of The Reaction ◽  
Solvent Free Reaction ◽  
Melt Phase

Reactions of (η5-RC5H4)Fe(CO)2I (R = H, Me) complexes with phosphine ligands PR′3 (R′ = Ph, m-Tol, p-C6H4OMe, p-C6H4Cl, p-C6H4F) have been performed under solvent-free conditions in the melt phase and generally yielded the ionic products [(η5-RC5H4)Fe(CO)2PR′3]I rather than the CO substituted products (η5-RC5H4)Fe(CO)(PR′3)I. The complexes have been characterised by IR, NMR and MS techniques. By contrast, the same reactions studied in benzene solution have yielded mainly the CO substitution products. Factors that affect the solvent-free reaction include variation in R and R′ , reaction temperature and the addition of [CpFe(CO)2]2 as a catalyst. The mechanism of the reaction for the formation of the ionic complex is proposed to go via a 19 electron intermediate. This is in contrast to the reaction in bezene that occurs via a 17 electron intermediate, clearly indicating the role of the melt phase in the reaction.

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