Syntheses and Coordination Chemistry of Chiral Phosphanyl Glycerols and Their Derivatives – X-ray Structure of (R)-Ph2P–CH2–CaH–O–B(Ph)–O–CbH2(Ca–Cb)

Novel C1-Bridged Bisboronate Derivatives by Insertion of Diazoalkanes into Bis(pinacolato)diborane(4)

“…The molecular structures of 5a , 5b , 5c , and 5d consist of a slightly distorted tetrahedral geometry for the central bridged carbon atom, for which the significant bond angles and bond lengths are summarized in Table . The average B−C(sp 3 ) bond lengths of 1.583 Å and the average B−O bond lengths of 1.371 Å are closely similar to the previously reported B−C bond lengths (1.575(5)−1.589(5) Å) and B−O bond lengths (1.364(9)−1.370(7) Å) in boronic acid esters. − The coordination at B(1) or B(2) is distorted trigonal planar with O−B−O average bond angles of 113.1° and O−B−C average bond angles of 123.4° and is in agreement with previously reported boronic esters. − The dioxaborolane rings in 5a , 5b , 5c , and 5d are slightly distorted to release the steric repulsion between the vicinal methyl groups in contrast to the almost planar structure of bis(pinacolato)diborane(4) and bis(catecolato)diborane(4). , The observed bond angles in 5a , O(3)−B(1)−O(2) 113.44°, B(1)−O(2)−C(5) 107.1°, B(1)−O(3)−C(5) 107.2°, and O(3)−C(4)−C(5) 102.1°, are also similar to those observed for 5b , 5c , and 5d . The degree of puckering of the five-membered C 2 O 2 B rings, as well as the dihedral angles between the mean planes of these rings, vary from one compound to another and to some extent from one ring to another within the same compound, Table .…”

Template controlled self-assembly of bidentate phosphine complexes with hemilabile coordination behaviour

“…The 31 P NMR spectra of 2a,b at 30 uC in DMF show broadened lines (d 76.4 (2a), 74.6 (2b)) at substantially higher chemical shifts than in the complex [trans-PdCl 2 (L 1 ) 2 ] (d 19.1) which is accessible from reaction of L 1 and 1; similar deshieldings had previously been observed for chelate complexes of related phosphinoalcohol ligands. 10 The observation of tin-satellites in the 31 P{ 1 H} and a triplet in the 119 Sn{ 1 H} NMR spectrum of 2b (d 2199.4, J Sn,P = 15 Hz) disclosed that the bimetallic aggregate remains kinetically stable and does not undergo ligand exchange (a 119 Sn NMR signal of 2a was unobservable in solution owing to its much lower solubility but the 119 Sn CP-MAS NMR spectrum of a solid sample shows one isotropic line at d iso = 2455).…”

A Phosphanyl‐Substituted Benzo‐1,3,2‐Dioxaborol as Ambiphilic Bifunctional Lewis Donor–Acceptor Unit

“…The 31 P NMR spectra of freshly prepared solutions of crystalline samples of 6 and 7 display single sharp lines at very similar chemical shifts [ δ ( 31 P) = 20.5 ( trans ‐ 6 ), 19.1 ppm ( trans ‐ 7 )] that are characteristic of similar trans ‐configured palladium diphosphane complexes 9. The onset of trans ‐/ cis isomerisation leads to the appearance of additional signals attributable to the cis isomers [ δ ( 31 P) = 30.6 ( cis ‐ 6 ), 31.2 ppm ( cis ‐ 7 )] and produces within several hours an equilibrium mixture that contains approximately 20–25 % (by integration of suitable NMR signals) of the cis isomers.…”