@article {32712, title = {Selecting Chiral BINOL-Derived Phosphoric Acid Catalysts: General Model To Identify Steric Features Essential for Enantioselectivity}, journal = {Chemistry {\textendash} A European Journal}, volume = {23}, year = {2017}, pages = {14248-14260}, abstract = {

Abstract Choosing the optimal catalyst for a new transformation is challenging because the ideal molecular requirements of the catalyst for one reaction do not always simply translate to another. Large groups at the 3,3\′ positions of the binaphthol rings are important for efficient stereoinduction but if they are too large this can lead to unusual or poor results. By applying a quantitative steric assessment of the substituents at the 3,3\′ positions of the binaphthol ring, we have systematically studied the effect of modulating this group on enantioselectivity for a wide range of reactions involving imines, and verified this analysis using ONIOM calculations. We have shown that in most reactions, the stereochemical outcome depends on both proximal and remote sterics. Summarising detailed calculations into a simple qualitative model identifies and explains the steric features required for high selectivity. This model is consistent with seventy seven papers reporting reactions (over 1000 transformations in total), and provides a straightforward decision tree for selecting the best catalyst.

}, keywords = {ASYMMETRIC CATALYSIS, binaphthol, catalyst choice, chirality, phosphoric acid}, doi = {10.1002/chem.201702019}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/chem.201702019}, author = {Reid, Jolene P. and Goodman, Jonathan M.} } @article {1527, title = {A simple, catalytic H-2-hydrogenation method for the synthesis of fine chemicals; hydrogenation of protoporphyrin IX dimethyl ester}, journal = {Tetrahedron Letters}, volume = {47}, number = {29}, year = {2006}, note = {ISI Document Delivery No.: 058XJTimes Cited: 2Cited Reference Count: 61Reboucas, Julio S. James, Brian R.}, month = {Jul}, pages = {5119-5122}, type = {Article}, abstract = {A conceptually simple H-2-hydrogenation protocol is introduced for the high-yield preparation of a natural product derivative. Protoporphyrin IX dimethyl ester is hydrogenated to the mesoporphyrin analogue in N,N-dimethylacetamide under H-2 (1 atm) at 80 degrees C within 30 min. The reaction is catalyzed by commercial RUCl3, without the need for the use of phosphine- and/or carbene-based ligands. (c) 2006 Elsevier Ltd. All rights reserved.}, keywords = {ASYMMETRIC CATALYSIS, CARBON-MONOXIDE, COMPLEXES, HEME OXYGENASE-1, HORSERADISH-PEROXIDASE, MESOPORPHYRIN, METALLOPORPHYRINS, NUCLEAR-MAGNETIC-RESONANCE, PORPHYRIN, RUTHENIUM(II) MYOGLOBIN}, isbn = {0040-4039}, url = {://000238697600028}, author = {Reboucas, J. S. and James, Brian R.} } @article {407, title = {Homo- and heterobimetallic precursor catalysts for the Heck reaction, and a proposal for a general catalytic cooperativity index}, journal = {Advanced Synthesis \& Catalysis}, volume = {344}, number = {10}, year = {2002}, note = {ISI Document Delivery No.: 629XZTimes Cited: 22Cited Reference Count: 58}, month = {Dec}, pages = {1126-1134}, type = {Article}, abstract = {Homo- (Pd-2) and heterobimetallic (PtPd) complexes supported by a P,P-bridging, bis(P,N-chelating) coordination mode of the potentially hexadentate ligand 1,1-bis[di(o-N,N-dimethylanilinyl)phosphino] methane (dmapm) are effective catalyst precursors for the aerobic Heck coupling of iodobenzene and styrene at 100degreesC in DMF/H2O solution containing K2CO3. This medium allows for trivial separation of the trans-stilbene product which precipitates after the reaction mixture is cooled. The bimetallic precursors are more active than predicted from the sum of the activities of complexes chosen to mimic their mono-metallic "half units," suggesting some degree of intermetallic cooperativity during the reaction. A non-linear dependence of initial rate on catalyst concentration implies, however, that the complexes do not remain intact, and may be involved in dissociative equilibria with non-dmapm containing monometallic components that are more active species for the Heck coupling. The complexes are slowly degraded by oxidation at a phosphorus centre. A general index for quantifying the degree of intermetallic cooperativity during a catalytic cycle is proposed and its utility and limitations are discussed.}, keywords = {aerobic), ASYMMETRIC CATALYSIS, bimetallic, CHEMISTRY, cooperativity, COORDINATION, COUPLING, Heck reaction (aqueous, HIGH REGIOSELECTIVITY, homogeneous, HYDROFORMYLATION, HYDROGEN, LIGANDS, NICKEL(II) SITE, palladium, PALLADIUM(II) COMPLEXES, phosphine (anilinyl), platinum, REACTIONS, thermomorphic, VINYLIC SUBSTITUTION-REACTIONS}, isbn = {1615-4150}, url = {://000180078900015}, author = {Jones, N. D. and James, Brian R.} }