In organic chemistry, atoms other than carbon and hydrogen are generally referred to as heteroatoms. The most common heteroatoms are nitrogen, oxygen and sulfur. Now I present to you an article called Chiral biphenyl diphosphines for asymmetric catalysis: stereoelectronic design and industrial perspectives, published in 2004-04-20, which mentions a compound: 52287-51-1, mainly applied to chiral biphenyl diphosphine nonracemic preparation ligand asym hydrogenation; SYNPHOS nonracemic preparation; DIFLUORPHOS nonracemic preparation; enantioselectivity hydrogenation ruthenium bidentate diphosphine ligand steric electronic effect; mol structure hydridochlororuthenium complex methyl acetoacetate DIFLUORPHOS; bite angle calculated bidentate diphosphine ligand; carbonyl stretching frequency carbonylchlororhodium complex bidentate diphosphine ligand, Recommanded Product: 6-Bromo-2,3-dihydrobenzo[b][1,4]dioxine.
Both enantiomers of the chiral diphosphines I (SYNPHOS) and II (DIFLUORPHOS) are prepared on multigram scales; the electronic and steric characteristics of I and II and of rhodium complexes derived from them are determined, compared with previous diphosphine catalysts, and correlated with their activities and enantioselectivities in the hydrogenation of ketones and olefins. I and II are prepared in five steps from 6-bromo-2,3-dihydro-1,4-benzodioxane and 5-bromo-2,2-difluorobenzodioxole, resp.; lithium-metal exchange and addition to a phosphoryl or phosphinyl chloride followed by oxidation to yield phosphine oxides, regioselective lithiation and iodination, Ullman coupling of the aryl iodides, resolution (either by acid-base resolution with di-O-benzoyl-tartaric acid or by chiral HPLC), and reduction of the phosphine oxides yields I and II in 38% and 33% overall yield, resp. The bite angles of I and II are compared to those of other common diphosphine ligands such as BINAP and MeO-BIPHEP. The structure of diastereomeric chlorohydridoruthenium complexes of (S)-II with Me acetoacetate is determined The C-O stretching frequencies of chloro(carbonyl)rhodium diphosphine complexes containing I, II, BINAP, and MeO-BIPHEP are determined as a measure of the electronic demands of the diphosphine ligands. β-Keto ester, α-keto ester, 1,3-diketone, ketone, and olefin substrates are hydrogenated in the presence of nonracemic I, II, BINAP, and MeO-BIPHEP and bis(η3-methallyl)(η4-1,5-cyclooctadienyl)ruthenium; the enantioselectivities are correlated with the steric and electronic properties of the ligands. The stereoelectronic features of the ligand and the substrate deeply influence the enantioselectivities obtained in asym. hydrogenation; whereas the steric and electronic factors for I (as in other diphosphines) correlate well, the bite angle of II does not correlate to its electronic effects in asym. hydrogenation reactions, leading to complementary hydrogenation selectivities for ligands I and II.
There is still a lot of research devoted to this compound(SMILES：BrC1=CC=C2OCCOC2=C1)Recommanded Product: 6-Bromo-2,3-dihydrobenzo[b][1,4]dioxine, and with the development of science, more effects of this compound(52287-51-1) can be discovered.
Reference:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics