Reinvestigation of the Substitutions Reaction of Stereogenic Phosphoryl Compounds: Stereochemistry, Mechanism, and Applications

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.

A Ni-catalyzed asymmetric C(sp)-P cross-coupling reaction for the synthesis of P-stereogenic alkynylphosphines

Due to the high reactivity of the triple bond, P-stereogenic alkynylphosphines could be easily derivatized, serving as universal building blocks for structurally diverse phosphine compounds. However, the synthesis of alkynylphosphines via direct P-C bond formation was unprecedented. Here, we report an efficient method for the synthesis of P-stereogenic alkynylphosphines with high enantioselectivity via a Ni-catalyzed asymmetric cross-coupling reaction. The reaction could tolerate a variety of functional groups, affording products that can be converted into useful phosphine derivatives.

Regioselective and stereoselective cleavages of P–S/C–S bonds by lithium and the formation of P-stereogenic functional phosphine derivatives

Various menthyl-containing phosphinothioates were prepared.

Cleavage of Aromatic C-O Bonds via Intramolecular SNAr Reaction and Preparation of P,C,Axial-Stereogenic Menthyl Phosphine Derivatives

Phosphine ligands with up to six chiral sites were prepared, starting from 2-phenylphenol, via O- and P-alkylation, cyclization, and coupling. The chirality was transferred from (L)-menthyl to phosphorus, α-carbon, and axis, to achieve excellent diastereoselectivities. During an intramolecular S_NAr reaction with alkoxyl as the leaving groups, the C-O bond was converted to a C-C bond. Both phosphine boranes and oxides could be used for the conversions, affording a series of cyclic phosphines.

Asymmetric Electrophilic Reactions in Phosphorus Chemistry

This review is devoted to the theoretic and synthetic aspects of asymmetric electrophilic substitution reactions at the stereogenic phosphorus center. The stereochemistry and mechanisms of electrophilic reactions are discussed—the substitution, addition and addition-elimination of many important reactions. The reactions of bimolecular electrophilic substitution SE2(P) proceed stereospecifically with the retention of absolute configuration at the phosphorus center, in contrast to the reactions of bimolecular nucleophilic substitution SN2(P), proceeding with inversion of absolute configuration. This conclusion was made based on stereochemical analysis of a wide range of trivalent phosphorus reactions with typical electrophiles and investigation of examples of a sizeable number of diverse compounds. The combination of stereospecific electrophilic reactions and stereoselective nucleophilic reactions is useful and promising for the further development of organophosphorus chemistry. The study of phosphoryl group transfer reactions is important for biological and molecular chemistry, as well as in studying mechanisms of chemical processes involving organophosphorus compounds. New versions of asymmetric electrophilic reactions applicable for the synthesis of enantiopure P-chiral secondary and tertiary phosphines are discussed.

The construction of three C–P bonds of P-stereogenic tertiary phosphines containing (l)-menthyl

A wide range of R_P or S_P-(l)-menthyl-containing SPOs were prepared via the reaction of 1,1′-bi(2-naphthol) derived phosphonite with a metallic reagent with excellent yield and dr.

Functional Phosphine Derivatives Having Stationary and Flexible Chiralities: Their Preparation and Chirality Controlling

Various functional secondary and tertiary phosphines, or their derivatives, containing stationary chiral phosphorus and flexible chiral axis were prepared, which could be further modified to afford diversely chelating ligands. The flexible axial chirality was fixed by stereogenic phosphorus via a cyclic linkage of chemical bonds or coordination with a metallic ion.

Nucleophilic Substitution in Solution: Activation Strain Analysis of Weak and Strong Solvent Effects

We have quantum chemically studied the effect of various polar and apolar solvents on the shape of the potential energy surface (PES) of a diverse collection of archetypal nucleophilic substitution reactions at carbon, silicon, phosphorus, and arsenic by using density functional theory at the OLYP/TZ2P level. In the gas phase, all our model SN 2 reactions have single-well PESs, except for the nucleophilic substitution reaction at carbon (SN 2@C), which has a double-well energy profile. The presence of the solvent can have a significant effect on the shape of the PES and, thus, on the nature of the SN 2 process. Solvation energies, charges on the nucleophile or leaving group, and structural features are compared for the various SN 2 reactions in a spectrum of solvents. We demonstrate how solvation can change the shape of the PES, depending not only on the polarity of the solvent, but also on how the charge is distributed over the interacting molecular moieties during different stages of the reaction. In the case of a nucleophilic substitution at three-coordinate phosphorus, the reaction can be made to proceed through a single-well [no transition state (TS)], bimodal barrier (two TSs), and then through a unimodal transition state (one TS) simply by increasing the polarity of the solvent.

Exploration of fluorescent organotin compounds of α-amino acid Schiff bases for the detection of organophosphorous chemical warfare agents: quantification of diethylchlorophosphate

Fluorescent Schiff base organotin probes for the detection of chemical warfare agents.