Use of .beta.-sulfonyl vinyl ketones as equivalents to vinyl ketones in the Robinson annelation. Convergent, highly stereoselective preparation of a hydrindanol related to vitamin D from 2-methylcyclopent-2-enone and lithiated (E)-but-2-enyldiphenylphosphine oxide

Tandem addition of nucleophilic and electrophilic reagents to vinyl phosphinates: the stereoselective formation of organophosphorus compounds with congested tertiary carbons

Carbon anions formed via the addition of Grignard reagents to SP-vinyl phosphinates were modified with electrophilic reagents to afford organophosphorus compounds with diverse carbon skeletons. The electrophiles included acids, aldehydes, epoxy groups, chalcogens and alkyl halides. When alkyl halides were used, bis-alkylated products were afforded. Substitution reactions or polymerization occurred when the reaction was applied to vinyl phosphine oxides.

Direct phosphorylation of benzylic C–H bonds under transition metal-free conditions forming sp3C–P bonds

Direct phosphorylation of benzylic C–H bonds with secondary phosphine oxides was first realized. The reaction was performed in organo/aqueous biphasic system and under transition metal-free conditions, proceeding via the cross dehydrogenative coupling.

Heterogeneous Catalytic Method for the Copper(II)-Catalysed Addition of H-Phosphinates and Secondary Phosphine Oxides to Phenylacetylene

Copper(II) on 4 Å molecular sieve was found to be an efficient heterogeneous catalyst in the addition of different H-phosphinates and secondary phosphine oxides to phenylacetylene. All hydrophosphinylation reactions were completely regioselective, as only β-isomers were formed, and the E-alkenylphosphinates and E-alkenylphosphine oxides were synthesized in moderate to excellent yields. The catalyst could be reused multiple times in the reaction.

Graphic Abstract

2-[Anilino(diphenylphosphoryl)methyl]phenol from a three-component Kabachnik-Fields reaction

The title compound, C25H22NO2P, was synthesized in high yield by a three-component Kabachnik-Fields reaction of diphenylphosphine oxide, salicylaldehyde and aniline in dry toluene at room temperature. It precipitates as racemic crystals, in which strong hydrogen bonds between the hydroxy group and the P=O group of a neighbouring molecule form one-dimensional heterochiral chains along the crystallographic a axis, with an O···O separation of 2.568 (2) Å. The pseudo-tetrahedral environment of the P atom is distorted, with O-P-C bond angles significantly larger than the C-P-C angles.

Cu-catalyzed asymmetric allylic alkylation of phosphonates and phosphine oxides with Grignard reagents

An efficient and highly enantioselective copper-catalyzed allylic alkylation of phosphonates and phosphine oxides with Grignard reagents and Taniaphos or phosphoramidites as chiral ligands is reported. Transformation of these products leads to a variety of new phosphorus-containing chiral intermediates.

(Z)-(1,2-Dichlorovinyl)diphenylphosphine oxide

The title compound, C₁₄H₁₁Cl₂OP, was synthesized by the reaction of diphenyl­phosphine oxide with 1,2-dichloro­ethyne under CuI catalysis. The reaction provided the Z isomer regioselectively. Two O—P—C bond angles [114.3 (1) and 112.5 (1)°] are significantly larger than the C—P—C [107.7 (1), 105.6 (1) and 106.6 (1)°] and another O—P—C angle [109.5 (1)°], indicating significant distortion of the tetra­hedral configuration of the P atom. In the crystal, mol­ecules are linked by weak inter­molecular C—H⋯O hydrogen bonds into centrosymmetric dimers, which are connected by further C—H⋯O inter­actions into chains along [101].

Copper-catalyzed addition of H-phosphine oxides to alkynes forming alkenylphosphine oxides

We have developed efficient copper-catalyzed additions of P(O)H compounds to alkynes, and the reactions provided the regio- and stereoselective E-alkenylphosphine oxides under catalysis of the commercially available and inexpensive copper catalyst system CuI/ethylenediamine. This finding is the first example of copper-catalyzed hydrophosphinylation of alkynes to synthesize alkenylphosphine oxides.

Tridemethylisovelleral, a potent cytotoxic agent

The synthesis and in vitro cytotoxicity toward various tumor cell lines of (+/-)-tridemethylisovelleral, an analogue of the bioactive fungal sesquiterpene (+)-isovelleral retaining the bicyclo[4,1,0]hept-2-en-1,2-dicarbaldehyde system but lacking the three methyl groups, is reported. The cytotoxicity of tridemethylisovelleral toward several tumor cell lines was found to be comparable with those of established antitumor drugs, and significantly higher than that of isovelleral.

Asymmetric conjugate additions of chiral phosphonamide anions to alpha,beta-unsaturated carbonyl compounds. A versatile method for vicinally substituted chirons

Reactions of anions derived from chiral nonracemic allyl, crotyl, and cinnamyl bicyclic C(2)-symmetrical phosphonamides with alpha, beta-unsaturated cyclic ketones, esters, lactones, and lactams take place at the gamma-position of the reagents. The products are diastereomerically pure or enriched beta-substituted carbonyl compounds. The method also provides easy access to vicinal substitution of as many as three stereogenic centers including in some cases quaternary carbon atoms, in a one-pot sequence.

Asymmetric synthesis of functionalized carbocycles and heterocycles

Anions of 1-halo-4-hexenyl phosphonamides derived from chiral, enantiopure C2 symmetrical 1,2-diamino cyclohexane react at the gamma-position in conjugate addition reactions with alpha, beta-unsaturated carbonyl compounds such as cyclopentenone, 4-(H)-furanone, pyrroline-2-one, and cinnamates to give functionalized adducts. Addition to imines is also possible. The adducts can be transformed into enantiopure or enriched carbocyclic and heterocyclic compounds bearing useable functionality.