Novel synthesis of P-chiral 1,3-oxaphospholane starting from optically pure propylene oxide is described. The exact structure is confirmed by X-ray crystallographic analysis.

An efficient methodology for synthesizing a small library of easily tunable and sterically bulky ligands for asymmetric hydroformylation (AHF) has been reported. Five groups of alkene substrates have been tested with excellent conversions, moderate-to-excellent regio- and enantioselectivities. Among the best result of the reported literature, application of ligand 1 c in the highly selective AHF of the challenging substrate 2,5-dihydrofuran yielded almost one isomer in up to 99 % conversion along with enantiomeric excesses (ee) of up to 92 %. Highly enantioselective AHF of dihydropyrrole substrates is achieved using the same ligand, with up to 95 % ee and up to >1:50 β-isomer/α-isomer ratio.

Asymmetric hydrogenation of unprotected NH imines catalyzed by rhodium/bis(phosphine)-thiourea provided chiral amines with up to 97 % yield and 95 % ee. ¹H NMR studies, coupled with control experiments, implied that catalytic chloride-bound intermediates were involved in the mechanism through a dual hydrogen-bonding interaction. Deuteration experiments proved that the hydrogenation proceeded through a pathway consistent with an imine.

Iridium-catalyzed asymmetric hydrogenation of N-alkyl-2-alkylpyridinium salts provided 2-aryl-substituted piperidines with high levels of enantioselectivity. Simple benzyl and other alkyl groups successfully activated the challenging pyridine substrates toward hydrogenation. The use of the unusual chiral-phosphole-based MP²-SEGPHOS was the key to the success of this approach which provides a versatile and practical procedure for the synthesis of chiral piperidines.

The high enantioselective rhodium-catalyzed hydroformylation of 1,1-disubstituted allylphthalimides has been developed. By employing chiral ligand 1,2-bis[(2S,5S)-2,5-diphenylphospholano]ethane [(S,S)-Ph-BPE], a series of β³-aminoaldehydes can be prepared with up to 95% enantioselectivity. This asymmetric procedure provides an efficient alternative route to prepare chiral β³-amino acids and alcohols.

High enantioselectivities (up to 99% ee) have been observed for the catalytic asymmetric hydrogenation of the α-ketone enol acetates. DuanPhos has been proved to be the most effective ligand for this reaction. The high yield and enantioselectivity of the asymmetric hydrogenation of the α-ketone enol acetates represents a feasible synthetic route to important pharmaceutical building blocks: α-hydroxy ketones.

New tetraphosphorus ligands have been developed and applied in the rhodium-catalyzed regioselective hydroformylation of a variety of functionalized allyl and vinyl derivatives. Remarkably high linear selectivity was obtained by these tetraphosphorus ligands. The ligand that bears strong electron-withdrawing 2,4-difluorophenyl groups is the most effective one in affording linear aldehydes. The Rh/tetraphosphorus ligand catalyst is highly effective to produce linear aldehydes from functionalized allyl derivatives with heteroatoms or aromatic groups directly adjacent to the allyl group. For vinyl derivatives, the ligand is highly linear selective for acrylic derivatives, styrene, vinyl pyridine, and vinyl phthalimide. Linear to branch ratios of 26:1 and 10:1 were obtained for the hydroformylation of styrene and allyl cyanide, respectively.

A new class of substituted tetraphosphine ligands has been applied in the rhodium-catalyzed regioselective isomerization–hydroformylation of internal olefins. The rhodium/tetraphosphine ligand system is highly effective for the isomerization and hydroformylation of 2-alkenes to form linear aldehydes. Greater than 95% linear selectivity and up to 94% yield of the total aldehydes were obtained for 2-pentene, 2-hexene and 2-octene. The catalyst system also showed high to moderate linear selectivity for the isomerization and hydroformylation of 3-hexene, 3-octene and 4-octene but with slow reaction rates.

A highly efficient and enantioselective hydrogenation of unprotected β-ketoenamines catalyzed with ruthenium(II) dichloro{(S)-(−)-2,2′-bis[di(3,5-xylyl)phosphino]-1,1′-binaphthyl}[(2S)-(+)-1,1-bis(4-methoxyphenyl)-3-methyl-1,2-butanediamine] {Ru[(S)-xylbinap][(S)-daipen]Cl₂} has been successfully developed. This methodology provides a straightforward access to free γ-secondary amino alcohols, which are key building blocks for a variety of pharmaceuticals and natural products, with high yields (>99%) and excellent enantioselectivities (up to 99% ee) in all cases.

Asymmetric hydrogenation of α-dehydroamino ketones catalyzed by a rhodium-chiral phosphorus ligand complex (up to 99% ee, 1000 TON), represents an efficient approach to chiral α-amino ketones. The reduction of α-amino ketones catalyzed by palladium on carbon (Pd/C) leads to amphetamine precursors with quantitative yield and no significant enantioselectivity loss.

A highly regioselective hydroaminomethylation of terminal olefins catalyzed by Rh complexes with 2, 2′, 6, 6′-tetrakis ((diphenylphosphino)methyl)-1, 1′-biphenyl (Tetrabi) ligand has been developed. Up to 99 % amine selectivity, 168 linear/branched amine product ratio (n/i), and 97.4 % linear amine yield has been obtained at a substrate/rhodium precursor ratio (S/Rh) of 1000 with this methodology. The turnover number was achieved 6930 at 10000 S/Rh ratio, and the n/i can reach up to >525. Several different olefins and secondary amines have been applied successfully with high chemoselectivity (99 %), yield (>98 %), and regioselectivity (>120).

A series of C₃*-TunePhos chiral diphosphine ligands has been successfully applied in the iridium-catalyzed enantioselective hydrogenation of quinolines, and this methodology provided an efficient access to a variety of optically active tetrahydroquinolines with up to 93% ee. Furthermore, attempts on the asymmetric hydrogenation of quinoline N-oxide are also discussed.

A highly efficient strategy for the synthesis of a series of chiral bisaminophosphine ligands was well established with several remarkable features. The synthetic utility of these ligands was explored for rhodium-catalyzed asymmetric hydrogenations of α-dehydroamino acid esters. Up to 98% ee values were achieved for the enantioselective synthesis of aminocarboxylic acids and their derivatives, which are very important chiral building blocks for the synthesis of a variety of natural products and biologically active molecules.

A catalytic complex made from [Ir(COD)Cl]₂ [di-μ-chloro-bis(1,5-cyclooctadiene)diiridium(I)] precursor and (S,S)-f-Binaphane ((R,R)-1,1′-bis{(R)-4,5-dihydro-3H-dinaphtho[1,2-c:2′,1′-e]phosphepino}ferrocene) ligand effectively catalyzed the enantioselective hydrogenation of cyclic imines with high reactivity and good enantioselectivity.

A new class of substituted tetraphosphane ligands has been developed and applied in the rhodium-catalyzed regioselective hydroformylation of terminal olefins. The high regioselectivity (linear selectivity is above 97 % for 1-octene and 1-hexene) at high temperature (140 °C) shown by these tetraphosphane ligands is remarkable considering the low regioselectivity commonly observed under similar reaction conditions when other bisphosphane analogues are used. The steric and electronic effects of substituents on the diarylphosphane moiety have also been examined.

A series of hybrid phosphine–phosphoramidite ligands has been designed and synthesized in moderate yields from chiral BINOL (1,1′-bi-2-naphthol) or NOBIN (2-amino-2′-hydroxy-1,1′-binaphthyl). They have achieved highly regio- and enantioselectivities in Rh-catalyzed asymmetric hydroformylations of styrene derivatives (branched/linear ratio up to 56.6, ee up to 99 %), vinyl acetate derivatives (up to 98 % ee), and allyl cyanide (up to 96 % ee). Systematic variation of ligand structure showed that the steric factor on the phsophoramidite moiety determined the performance of the ligand. With the increased hindrance, the branched/linear ratio rose, while the ee value dropped in the hydroformylation of styrene. However, the N-substituents did not influence the selectivities much.

A highly efficient strategy for the synthesis of a series of C₃*-TunePhos chiral diphosphine ligands was well established with several remarkable features. The synthetic utility of these ligands was explored for the ruthenium-catalyzed asymmetric hydrogenation of β-keto esters. Up to 99% ee values were achieved for the enantioselective synthesis of β-hydroxy acid derivatives, which are very important chiral building blocks for the synthesis of a variety of natural products and biologically active molecules.

A catalytic method employing the cationic iridium-(S_c,R_p)-DuanPhos [(1R,1′R,2S,2′S)-2,2′-di-tert-butyl-2,2′,3,3′-tetrahydro-1H,1′H-1,1′-biisophosphindole] complex and BARF {tetrakis[3,5-bis(trifluoromethyl)phenyl]borate} counterion effectively catalyzes the enantioselective hydrogenation of acyclic N-arylimines with high turnover numbers (up to 10,000 TON) and excellent enantioselectivities (up to 98% ee), achieving the practical synthesis of chiral secondary amines.