87682-05-1

Upstream product

• 87682-04-0 3,3'-Dibromo-5,5'-dimethyl<1,1'-biphenyl>-2,2'-diol 
• 98-80-6 phenylboronic acid 
• 39579-09-4 5-methylbiphenyl-2-ol 
• 79115-30-3 3,3'-Dibromo-2,2'-dimethoxy-5,5'-dimethyl<1,1'-biphenyl> 

Downstream Products

• 87682-07-3 6,7,9,10,12,13,15,16,18,19-decahydro-4,21-diphenyl-2,23-dimethyldibenzo<1,4,7,10,13,16>hexaoxacycloeicosin 

Relevant academic research and scientific papers

Oxidative photocatalytic homo- And cross-coupling of phenols: Nonenzymatic, catalytic method for coupling tyrosine

An oxidative photocatalytic method for phenol? phenol homo- and cross-coupling is described, and isolated yields of 16?97% are obtained. Measured oxidation potentials and computed nucleophilicity parameters support a mechanism of nucleophilic attack of one partner onto the oxidized neutral radical form of the other partner. Our understanding of this model permitted the development of cross-coupling reactions between nucleophilic phenols/arenes and easily oxidized phenols with high selectivity and efficiency. A highlight of this method is that one equivalent of each coupling partner is utilized. Building on these findings, a nonenzymatic, catalytic method for coupling tyrosine was also developed.

Synthesis, complexation behavior and catalytic performance of chelating bisphosphite ligands based on 9,10-brigded 9,10-dihydroanthracenes in Rh catalyzed hydroformylation of 4-pentenal

In the present work the modular synthesis of new chelating bisphosphite ligands based on 9,10-brigded 9,10-dihydroanthracenes as ligand backbones is presented. The complexation behavior of these ligands in rhodium metal complexes as well as mechanistic studies of the preformation step of the rhodium-catalysed hydroformylation is investigated. Ratio of coordination isomers in the Rh complexes of these ligands has been determined using NMR based calculation technique. Modular synthesis route was established allowing for a variety of ligands to be synthesized in a standard procedure The new ligands were tested in the hydroformylation of 4-pentenal under optimized conditions to give adipic aldehyde a promising starting material for the polyamide nylon-6,6. Ligand L3 showed the best selectivity towards adipic aldehyde with selectivity of 10.2/1 n/iso aldehyde.

Synthesis of Adipic Aldehyde by n-Selective Hydroformylation of 4-Pentenal

Several phosphine and phosphite ligands were tested in the hydroformylation of 4-pentenal to adipic aldehyde, a versatile starting material for industrially very relevant compounds. By varying the ligand structure we were able to increase the selectivity toward adipic aldehyde to >95%. Additionally, two molecular structures of important catalytic intermediates [(bisphosphite)RhH(CO)2] and one structure of a previously unknown catalyst decomposition product were obtained. (Chemical Equation Presented).

Host-Guest Complexation. 25. Effects of Substituents on the Complexing Properties of Chorands

The syntheses of three benzannelated 18-crown-6 chorands (3,6,and 7) and three dibenzo-20-crown-6 chorands (10b-d) are reported, along with their free energies of association toward Li+, Na+, K+, Rb+, Cs+, NH4+, CH3NH3+, and t-BuNH3+ picrates in CDCl3 at 25 deg C.For the 18-membered chorands, as well as previously reported paracyclophane-18-crown-6 hosts and naphtho-18-crown-6 hosts, the average negative free energies of association (-ΔG0av)for Li+, Na+, K+, Rb+, Cs+, and NH4+ picrates were qualitatively correlated with the degree of coplanarity of β-aryl substituents and the aromatic rings.The results are interpreted in terms of conformational organization of ligating sites in comparision with organization observed in crystalline complexes.Substuents were found to enhance complexation in the dibenzo-20-crown-6 series.This is interpreted as an effect of ligating-site preorganization and free-host destabilization.Substituent effects in chiral bicyclohexyl (13) and meso-bicyclohexyl hosts (14) are explained in similar terms.

Process for the production of 2,2'-dihydroxy-biphenyls

A process for the production of 2,2'-dihydroxy-biphenyls of the formula I STR1 wherein the symbols are as defined in claim 1. The process consists in the oxidative coupling of a phenol of the formula II STR2 in the presence of a strong inorganic base, with hydrogen peroxide as oxidizing agent. The reaction temperature is in the range from 30° to 100° C. and 1.5 to 4 moles of a base are employed per mole of phenol of the formula II.