Synthesis Without Metals

In this chapter, examples of achiral organocatalysts are briefly described and chiral organocatalysts are mainly discussed. 

Handbook of Green Chemistry Volume 7 Green Synthesis, First Edition. Edited by Chao-Jun Li. 

---

Ni and Co or of oxophilic metals, for example. Re, is still poorly studied the surface-mediated synthesis of bimetallic carbonyl clusters is limited to a few examples the surface-mediated synthesis of metal compounds without carbonyl ligands has just begun with the silica-mediated synthesis of [RhH2(PMe3)4] by treatment of bis (allyl) rhodium with PMe3 followed by H2 [121] the silica-mediated synthesis of tantalum clusters has been investigated recently but the products were not extracted from the surface-for example, treatment of silica physisorbed Ta(CH2Ph)5 in H2 at 523 K for 20 h led to tri-tantalum clusters, as shown by EXAFS spectroscopy [122]. 

The application of Schiff base chemistry to the synthesis of heterophanes possessing diverse subunits has been reviewed in part (82MI52202, B-79MI52201). An example of this procedure is the treatment of (19) with 2,3-diaminopyridine, with or without metal ion templation, to give (20) as an isomeric mixture (75MI52200). 

Di-iminoisoindoline was used as a precursor for Pc in different protic and aprotic systems, without catalysts or promoters, to study the solvent effect on the possibility of phthalocyanine formation [32], As can be observed (Example 13), it is possible to carry out the chemical and electrochemical synthesis of metal-free Pc in aprotic solvents, such as DMF or DMSO, in contrast to the results with PN. It is surprising that the yields of Pc in ROH are comparatively small. The N,N-dimethyletanolamine is characterized by the best yields, as in the case when PN was used as precursor. 

Beck, W. Niemer, B. Wieser, M. Methods for the synthesis of p-hydrocarbon transition metal complexes without metal-metal bonds. Angew. Chem. Int. Ed. Engl. 1993, 32(7), 923-949. 

In this chapter, stable polyyne-type compounds and materials are surveyed with regard to their synthesis, properties, and possible applications. They are classified into end-capped polyynes with or without metals and alternating co-polymers having a polyyne unit with or without metals. In order to determine the possible application of polyynes, the detailed chemical and physical properties in solution, and in the liquid, and solid states, must be known. 

The complex composition of the systems using O2/H2 oxidant gives evidence that pure metal catalysts do not operate effectively without promoter, which can be halide ions and/or transition metal oxides. Our idea was to bring into contact platinum metal ions with probable promoter by means of synthesis of metal ion containing heteropolytungstates. 

Organohalogen metabolites are produced by bacteria, fungi, and algae by haloperoxidases that contain protoporphyrin IX, vanadium (V), or are without metals, and catalyze their synthesis in the presence of H202, formally by production of Hal+ (Neidleman and Geigert 1986). 

---