A catalyst don’t appear in the overall stoichiometry of the reaction it catalyzes, category: catalyst-ligand, but it must appear in at least one of the elementary reactions in the mechanism for the catalyzed reaction. 18531-94-7, Name is (R)-[1,1′-Binaphthalene]-2,2′-diol, molecular formula is C20H14O2. In a Article, authors is Foubelo, Francisco£¬once mentioned of 18531-94-7
Reductive ring opening of dihydrodibenzothiepine and dihydrodinaphtho- oxepine and -thiepine
The 4,4?di-tert-butylbiphenyl (DTBB)-catalysed lithiation of dihydrodibenzothiepine (1) at -78C for 30 min followed by reaction with a carbonyl compound [tBuCHO, Ph(CH2)2CHO, PhCHO, (n-C5H11)2CO, (CH2)5CO, (CH2)7CO, (-)-menthone] at the same temperature leads, after hydrolysis with 3 M hydrochloric acid, to sulphanyl alcohols 2. If after addition of a carbonyl compound as the first electrophile [Me2CO, (CH2)5CO, (-)-menthone], the resulting dianion of type II is allowed to react at room temperature for 30 min, a second lithiation takes place to give an intermediate of type III, which by reaction with a second electrophile [Me2CO, Et2CO, (CH2) 5CO, ClCO2Et], yields, after hydrolysis, difunctionalised byphenyls 4. The cyclisation of the sulphanyl alcohol 2c under acidic conditions yields the eight-membered sulphur containing heterocycle 3. The lithiation of dihydrodinaphthoheteroepines 7 and 10 with 2.2 equiv of lithium naphthalenide in THF at -78C followed by reaction with different electrophiles [H 2O, D2O, tBuCHO, Me2CO, Et 2CO, (CH2)4CO, (CH2)5CO] at the same temperature leads, after hydrolysis, to unsymmetrically 2,2?-disubstituted binaphthyls 9 and 12, respectively. When the lithiation is performed with an excess of lithium in the presence of a catalytic amount of DTBB (10% molar), a double reductive cleavage takes place to give the dianionic intermediate VII, which by reaction with different electrophiles [H 2O, Me2CO, Et2CO, (CH2) 4CO, (CH2)5CO], followed by hydrolysis with water, yields symmetrically 2,2?-disubstituted binaphthyls 8 and 11. In the case of starting from (R)- or (S)-dihydrodinaphthoheteroepines 7 and 10, these methodologies allow us to prepare enantiomerically pure compounds 8, 11 and 12.
Enzymes are biological catalysts that produce large increases in reaction rates and tend to be specific for certain reactants and products. I hope my blog about is helpful to your research. category: catalyst-ligand
Reference£º
Metal catalyst and ligand design,
Ligand Template Strategies for Catalyst Encapsulation – NCBI