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An efficient base-catalyzed double addition of H-phosphine oxides to alkynes is developed. In the presence of a catalytic amount of a base, the addition of various H-phosphine oxides to both aromatic and aliphatic alkynes took place efficiently to produce the corresponding bisphosphoryl compounds in excellent yields. This method provides an easy direct way to prepare bisphosphine oxides that are of high importance in organic synthesis.

A Pd-catalyzed dehydrogenative phosphorylation of thiols is developed. A variety of thiols dehydrogenatively couple readily with all three kinds of P(O)–H compounds, i.e., H-phosphonates, H-phosphinates, and secondary phosphine oxides, providing a general access to the valuable phosphorothioates including the P-chiral compounds. A plausible mechanism is proposed.

The nickel-catalyzed α-benzylation of sulfones with readily available benzylic alcohol derivatives was achieved via C–O activation. The transformation was complete in 30 minutes using a simple Ni(COD)2 as a catalyst without any additional ligands. A variety of substituted sulfones including the building block for bioactive compound eletriptan were synthesized by using the strategy.

Optically active α-hydroxyphosphinates with both C- and P-stereogenic centers are obtained by rhodium- or iridium-catalyzed substrate-directed stereoselective addition of the optically pure H-phosphinates to aldehydes. The reaction most probably proceeds by a transition-metal-catalyzed mechanism with hydridometal complexes as key intermediates in the catalytic cycle.

An efficient nickel-catalyzed phosphorylation of phenol derivatives with P(O)-H compounds via C-O/P-H cross-coupling is described. Under the reaction conditions, various phenyl pivalates coupled readily with hydrogen phosphoryl compounds to afford the corresponding coupling products aryl phosphonates and aryl phosphine oxides in good to high yields.

Various α-benzylated arylacetonitriles are prepared under mild conditions by Ni-catalyzed direct cross-coupling reactions of benzylic alcohol derivatives with arylacetonitriles via C—O activation.

A simple and environmentally benign method was developed for the synthesis of chalcones in high to excellent yields by a phosphorous acid promoted alkyne–aldehyde hydration–condensation in an oil/water two-phase system. The method is the first efficient protocol for the preparation of chalcones that is mediated by a simple Bronsted acid in a two-phase system.

An efficient Ni-catalyzed synthesis of (E)-olefins using the readily available benzylic alcohol derivatives and arylacetonitriles is described. This transformation should proceed via a tandem process involving nickel-catalyzed cross coupling via C-O activation and subsequent stereoselective E2 elimination.

Review: recent progress in the preparation of organo-phosphorus compounds via transitin metal-catalyzed dehydrogenative couplings of P(O)H compounds; 79 refs.

Chloroform replaces the highly toxic CCl4 as halogenating reagent and solvent in Atherton—Todd-type reactions of alcohols and thiols with secondary phosphine oxides.

The first copper-catalyzed aerobic oxidative C(aryl)OH bond functionalization of catechols is reported. Under air, at room temperature, in the presence of a copper catalyst, catechols react with amines to produce the corresponding benzoxazoles in high yields. Mechanistic studies suggest that the reaction proceeds via an intriguing competitive oxidation and a synergetic catalysis between catechol and amine.

A broad range of hetaromatics is amidated with ammonium acetate, including 2-methylquinolines equipped with various functional groups, 2-methyl and 2-ethylpyridine, 2-methylthiophene and 2-methylthiazole.

Arylphosphine oxides (III) and (V) as well as arylphosphines (VII) are readily prepared by a Ni-catalyzed cross-coupling of aryl nitriles with the corresponding P—H compounds.

In this account, we summarize our recent work on the preparation of optically active H-phosphinates and their stereospecific transformations, including regio- and stereospecific additions, nucleophilic substitutions with organolithiums and Grignard reagents, halogenation with copper(II) chloride, and dehydrogenative couplings with heteroatom–hydrogen bonds. These reactions provide efficient ways for the synthesis of valuable, optically active, P-stereogenic, organophosphorus compounds from relatively easily prepared, enantiomerically pure, menthyl hydrogen phosphinates. The applications of optically active H-phosphinates in catalytic asymmetric hydrogenations are also discussed. 1 Optically Pure Menthyl Hydrogen Phosphinates: Easily Accessible P-Stereogenic Starting Materials 2 Optically Pure Menthyl Hydrogen Phosphinates as Starting Materials for the Synthesis of P-Chiral Compounds 2.1 Stereospecific Additions 2.1.1 Additions to Alkynes 2.1.2 Addition to Alkenes 2.1.3 Addition to p-Quinones 2.1.4 Additions to Ketones or Aldehydes 2.2 Stereospecific Nucleophilic Substitution by Organolithiums or Grignard Reagents 2.3 Stereospecific Halogenation with Copper(II) Chloride 2.4 Stereospecific Cross-Dehydrogenative Coupling with Nucleo­philes (Amines, Alcohols, Thiols, etc.) 2.5 Stereospecific Cross-Coupling with C–X Bonds 3 Asymmetric Catalytic Hydrogenation Reactions with Optically Pure Menthyl Hydrogen Phosphinates as Ligands 4 Conclusion

An efficient strategy is developed which allows the preparation of various types of phosphorus compounds from pivalates and different P—H reagents.

The Ni-catalyzed direct C–H/C–O cross couplings of benzylic alcohol derivatives with fluorobenzenes and heteroarenes are disclosed. This transformation provides a straightforward and efficient method for the synthesis of these valuable heteroatom-containing compounds.

Catalyst-free and selective C–N bond functionalization has been achieved through three-component coupling of amines, dihalomethane, and >P(O)H species. This reaction takes place stereospecifically with retention of configuration at phosphorus, which can produce various new optically active phosphorus analogues of α-amino acids.

The atom-efficient one-pot synthesis succeeds using aromatic aldehydes and aromatic conjugated aldehydes, but fails using the corresponding aliphatic compounds or ketones.

A copper-catalyzed aerobic oxidative amidation reaction of inert C-C bonds with tertiary amines has been developed for the synthesis of tertiary amides, which are significant units in many natural products, pharmaceuticals, and fine chemicals. This method combines C-C bond activation, C-N bond cleavage, and C-H bond oxygenation in a one-pot protocol, using molecular oxygen as the sole oxidant without any additional ligands.

A copper-catalyzed system for the amidation of carboxylic acids with tert-amines through C–N bond cleavage was developed. This protocol is practical and represents a simple way to produce functionalized amides from basic starting materials in moderate to good yields. A plausible mechanism is proposed for the reaction.

A combination of dibromomethane and dimethylaniline as reagents is employed as source of HBr for the hydrobromination of alkynes to afford the Markovnikov-type vinyl bromides in good yields.

An efficient synthesis of 2-hetarylquinazolin-4(3H)-ones via copper-catalyzed direct aerobic oxidative amination of sp3C–H bonds has been developed. This tandem oxidation–amination–cyclization transformation represents a straightforward protocol to prepare 2-hetaryl-substituted quinazolinones from easily available 2-aminobenzamides and (2-azaaryl)methanes.

The immobilized catalyst can be easily recovered from the reaction mixture via simple centrifugal separation and reused several times without severe deactivation.

Copper-catalyzed stereospecific oxidative dehydrocouplings of P(O)–H bonds with amines under air took place efficiently at room temperature to afford the corresponding amidophosphorus compounds in ...

The optimized conditions allow the selective semihydrogenation of a broad range of terminal aromatic and aliphatic alkynes to afford the corresponding alkenes in high yields.

A facile Ni-catalyzed semihydrogenation of internal alkynes to ( E )-alkenes using the cheap and easily handled hypophosphorous acid as a hydrogen donor was described. This reaction is featured by high reaction efficiency to produce the corresponding ( E )-alkenes selectively.

A simple, efficient and highly functional group compatible method for the synthesis of propargylamines from terminal alkynes, dichloromethane and tertiary amines using silver catalysts has been developed.

A highly selective head-to-tail dimerization of aliphatic and aromatic alkynes (I) and (III) is reported.

The catalytic hydrogenation of alkynes such as (I) with formic acid can be controlled by changing the conditions to selectively produce (Z)-alkenes such as (II), (E)-alkenes such as (III), or alkanes such as (IV).