Synthesis of functionalized 1‐trimethylsiloxy‐substituted O‐trimethylsilyl alkylphosphonites and their derivatives

Nucleophilic addition of trimethylsilyl esters of tricoordinate organophosphorus acids to various functionalized aldehydes with vinyl, aryl, and heterocyclic fragments is proposed as a convenient method for the synthesis of new 1‐trimethylsiloxysubstituted alkylphosphonites and their derivatives at mild conditions. Also the new functionalized derivatives of these phosphonites, including amino groups as well as certain properties of these compounds as important precursors of new functionalized 1‐hydroxyalkylorganophosphorus acids, are presented. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:352–359, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20430     

New methods of synthesis of boron,germanium, and tin derivatives of pentavalent phosphorus thioacids

The reactions of S‐trimethylsilyl esters of S‐propyl‐4‐methoxyphenyltrithiophosphonic, bis(dialkylamido)dithiophosphoric, and S‐ethyl‐diethylamidotrithiophosphoric acids with trialkyl borates, triorganylbromogermanes, trimethyl(isobutylthio)germane, and trialkylchlorostannanes were studied. On the basis of these studies, new methods of synthesizing S‐boron, S‐germyl, and S‐stannyl derivatives of pentavalent phosphorus thioacids were developed. S‐Diethylaminomethyl O‐isopropyl‐4‐ethoxyphenyldithiophosphonate was obtained by the reaction of the diisopropylboron derivative of the corresponding dithiophosphonic acid with the aminal 6 . © 2002 John Wiley & Sons, Inc. Heteroatom Chem 13:27–35, 2002; DOI 10.1002/hc.1103     

Bis(trifluoroacetyl)phenols and their derivatives in reactions with selected phosphorus(III) compounds

The reactivity of bis(trifluoroacetyl)‐phenols toward selected λ³P derivatives was examined. In the case of dialkyl(isocyanato)phosphites, only one of both present trifluoracetyl moieties of substrate was involved. After addition of the phenolic OH moiety across the intermediary formed PN bond, tri‐, tetra‐, and pentacyclic α‐(trifluoromethyl)phosphoranes were produced in a highly diastereoselective reaction. An unusual deoxygenation of the intermediary hydroxyphosphorane was observed reacting 4‐methyl‐2,6‐bis‐(trifluoroacetyl)phenol with diethyl(trimethylsilyl)‐phosphite, and the subsequent hydrolysis gave γ‐hydroxy‐α‐(trifluoromethyl)phoshonate. On the contrary, during the reaction of the O‐silylated phenol with tris(trimethylsilyl)phosphite, a bis‐phosphonate was obtained that underwent heterocyclization to phosphono phosphole system. The mechanistic aspects of the studied reactions, as well as structural features of the synthesized compounds are discussed, based on the multinuclear NMR spectroscopy and X‐ray single crystal investigation data. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:474–482, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20451     

2‐Polyfluoroacylcycloalkanones in reactions with selected phosphorus(III) compounds

The reactivity of 2‐polyfluoroacylcycloalkanones and their O‐silylated derivatives towards phosphites and tris(trimethylsilyl)aminoiminophosphine has been investigated. From α‐polyfluoroalkyl substituted phosphonates, generated from tris(trimethylsilyl) phosphite and 1,3‐diketones, the respective phosphonic acids and their salts have been obtained. In one case, upon warming, a phosphonic acid underwent a ring closure to yield an oxaphospholene. 2‐Trifluoroacetylcycloalkanones and diethyl isocyanatophosphite furnished phosphoranes diastereospecifically, via addition of phosphorus at the trifluoroacetyl group and two additional heterocyclizations. Tris(trimethylsilyl)aminoiminophosphine formed very reactive trimethylsilylimino‐1,2λ⁵σ⁴‐phospholenes, which added hexafluoroacetone to give spirocyclic 1,3,2λ⁵σ⁵‐oxazaphosphetanes. The structures of the new compounds were determined by NMR spectroscopy and X‐ray single crystal analysis. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:97–107, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10001     

Synthesis and reactivity of alkoxy(trimethylsiloxy)phosphines and their derivatives

Convenient procedures for the synthesis of new alkoxy(trimethylsiloxy)phosphines and their derivatives starting from the available alkyl hypophosphites and N‐trimethylsilyl succinimide are proposed. Some properties of these new phosphines such as nucleophilic substitution of the trimethylsiloxy group at trivalent phosphorus, the Arbuzov reaction, and addition of PH and POSi fragments to multiple carbon–carbon bonds are presented. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 23:138–145, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20762     

Synthesis of bis‐ and tris‐organophosphorus substituted amines and amino acids with PCH2N Fragments

The aminomethylation of the derivatives of trivalent organophosphorus acids, containing PH and POSiMe₃ fragments with various bis‐ and tris(alkoxymethyl)amines and bis(alkoxymethyl)amino acids, is proposed as a convenient method for the synthesis of new bis‐ and trisphosphorylated amines and amino acids as well as their derivatives with four and five coordinated phosphorus. Also the three‐components systems of phosphorous acid, paraformaldehyde, and amines are thoroughly investigated via the treatment of reaction mixtures with bis(trimethylsilyl)amine. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:430–440, 2010; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20616     

Synthesis of phosphonodipeptide conjugates of ursolic acid and their homologs

To prepare novel derivatives of naturally bioactive 3β‐hydroxy‐urs‐12‐en‐28‐oic acid (ursolic acid) with unusual properties and broad spectrum of activities, a number of chemical reactions were conducted. First, a variety of α‐aminophosphonates were prepared by a series of reactions involving the three‐component Mannich type reaction as a key step. Second, an array of phosphonodipeptides and their homologs was synthesized through multistep reactions including condensation of phthalic anhydride with glycine or β‐alanine, chlorination of N‐blocked amino acids, coupling of acid chloride with α‐aminophosphonates and sequential hydrazinolysis. Finally, new classes of phosphonodipeptide conjugates of ursolic acid and their homologs were obtained by condensation of 3β‐acetoxy‐urs‐12‐en‐28‐oyl chloride with phosphonodipeptides and their homologs. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:55–65, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20396     

Synthesis of new organophosphorus‐substituted mono‐ and bis(trimethylsilyl)amines with PCH2N fragments and their derivatives

Convenient procedures for the synthesis of new organophosphorus‐substituted mono‐ and bis(trimethylsilyl)amines with PCH₂N moiety are proposed, starting from trimethylsilyl esters of organophosphorus acids, as well as 1,3,5‐trialkylhexahydro‐1,3,5‐triazines and N‐alkoxymethyl bis(trimethylsilyl)amines as aminomethylating reagents. Certain properties of the resulting compounds are presented. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:71–77, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20580     

Synthesis of peptidyl phosphonates containing 5‐(4′‐carboxyphenyl)‐10,15,20‐tritolylporphyrin

The synthesis and characterization of three new porphyrin‐peptidyl‐phosphonate derivatives, containing a diphenyl 3‐pyridylmethyl‐phosphonate moiety, is described. These compounds could serve as potential photosensitizers for the PDT method of tumor therapy and displayed activity as inhibitors of aminopeptidase N. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:107–111, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20407     

Phosphorylation of N‐Silylpyrroles with Phosphorus Tribromide

Phosphorylation of N‐trimethylsilyl‐ and N‐dimethyl‐tert‐butylsilylpyrroles with phosphorus tribromide in pyridine proceeds selectively at position 3 of the pyrrole ring. Removal of the trialkylsilyl protecting group has furnished the first representatives of N‐unsubstituted 3‐phosphorylated pyrroles. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:93–96, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20416     

Rh‐ and Pt‐catalyzed cycloisomerization of enynes derived from terpenes

The Rh‐catalyzed cycloisomerization of new terpenoid derivatives featuring an O‐tethered enyne unexpectedly leads to polycyclic derivatives containing an inner cyclopropane ring or a diene moiety, depending on the structure of the enyne, as observed in the PtCl₂‐catalyzed processes. Copyright © 2008 John Wiley & Sons, Ltd.     

Synthesis and characterization of polycholesteryl methacrylate–polyhydroxyethyl methyacrylate block copolymers

We report the synthesis and characterization of a series of novel diblock copolymers, poly(cholesteryl methacrylate‐b‐2‐hydroxyethyl methacrylate) (PCMA‐b‐PHEMA). Monomers, cholesteryl methacrylate (CMA) and 2‐(trimethylsiloxy)ethyl methacrylate (HEMA‐TMS), were prepared from methyacryloyl chloride and 2‐hydroxyethyl methacrylate, respectively. Homopolymers of CMA, PCMA, with well‐defined molecular weights and polydispersity indices (PDI), were prepared by reversible addition fragmentation and chain transfer (RAFT) method. Precursor diblock copolymers, PCMA‐b‐P(HEMA‐TMS), were synthesized using PCMA as macromolecular chain transfer agent and monomer, HEMA‐TMS. Product diblock copolymers, PCMA‐b‐PHEMA, were prepared by deprotecting trimethylsilyl units in the precursor diblock copolymers using acid catalysts. Detailed molecular characterization of the precursor diblock copolymers, PCMA‐b‐P(HEMA‐TMS), and the product diblock copolymers, PCMA‐b‐PHEMA, confirmed the composition and structure of these polymers. This versatile synthetic strategy can be used to prepare new amphiphilic block copolymers with cholesterol in one block and hydrogen‐bonding moieties in the second block. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6801–6809, 2008     

Synthesis of a new organogelator based on block structures of co‐oligoamide‐6

A series of new bisurea derivatives having in common two co‐oligoamide arms have been synthesized and characterized by NMR, SEC, DSC, SEM, and optical microscopy. These compounds are only soluble at high temperature in aprotic polar solvent. By cooling the solutions, gelation occurs if the concentration of these bisurea derivatives is higher than 3% (w/w). Comparisons with derivatives devoid of oligoamide arms leading no gelation suggest that two kinds of interaction are necessary to get the self‐assembling, namely intermolecular hydrogen‐bonding between urea groups and between oligoamide arms. As these interactions induce interconnections in several directions, the possibility of building the long classical fibrous structures is limited. Accordingly, the ultrastructure of the gel consists only of short interconnected fibers. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4122–4129, 2008     

Structural determination of nerve agent markers using gas chromatography mass spectrometry after derivatization with 3‐pyridyldiazomethane

Nerve agents are a class of organophosphorous chemicals that are prohibited under the Chemical Weapons Convention. Their degradation products, phosphonic acids, are analyzed as markers of nerve agent contamination and use. Because the phosphonic acids are non‐volatile and very polar, their identification by GC‐MS requires a derivatization step prior to analysis. Standard derivatization methods for gas‐chromatography electron‐impact mass‐spectrometry analysis give very similar spectra for many alkyl phosphonic acid isomers, which complicates the identification process. We present a new reagent, 3‐pyridyldiazomethane, for preparing picolinyl ester derivatives of alkyl methylphosphonic acids facilitating the determination of their structure by enhancing predictable fragmentation of the O‐alkyl chain. This fragmentation is directed by the nitrogen nucleus of the pyridyl moiety that abstracts hydrogen from the O‐alkyl chain, inducing radical cleavage of the carbon–carbon bonds and thereby causing extensive fragmentation that can be used for detailed structure elucidation of the O‐alkyl moiety. The separability of related isomers was tested by comparing the spectra of the picolinyl esters formed from twelve hexyl methylphosphonic acid isomers. Spectral library matches and principal component analysis showed that the picolinyl esters were more effectively separated than the corresponding trimethylsilyl derivatives used in the standard operating procedures. The suggested method will improve the unambiguous structural determination process for phosphonic acids. Copyright © 2013 John Wiley & Sons, Ltd.     

Synthesis of new functionalized mono‐ and bisphosphinates with 2,6‐di‐tert‐butyl‐4‐methylphenol fragments

Convenient procedures for the synthesis of functionalized mono‐ and bisphosphinates with 2,6‐di‐tert‐butyl‐4‐methylphenol (ionol) fragments, starting from the available 3,5‐di‐tert‐butyl‐4‐benzaldehyde and its derivatives, are proposed, and some properties of the new phosphorus‐substituted sterically hindered phenols are presented. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:562–568, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20475     

Synthesis of the New Types of N‐Unsubstituted Aminomethylenebisorganophosphorus Acids and Their Derivatives

The interaction of trimethylsilyl esters of trivalent organophosphorus acids containing PH and POSiMe₃ groups with hydrochlorides of ethoxymethylene imines is a convenient method for the synthesis of new trimethylsilyl esters of N‐unsubstituted aminomethylenebisorganophosphorus acids with three and four coordinated phosphorus. Also trimethylsilyl trifluoromethanesulfonate as effective catalyst is used for the similar interaction of hydrochlorides of ethoxymethylene imines with tris(trimethylsilyl)phosphite. The corresponding bisorganophosphorus acids and their derivatives are presented.     

Catalytic synthesis of oligoene and enyne derivatives through carbometalation of internal alkynes

A number of new synthetic methods for π‐conjugated oligoene and enyne compounds are described. Thus, diene and higher oligoene derivatives are selectively constructed by palladium‐catalyzed arylation reactions of internal alkynes in the presence of arylboronic acids or alkenes as terminators. In contrast, the synthesis of various enyne derivatives is achieved effectively by homo‐ or cross dimerization of alkynes under rhodium catalysis. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 326–336; 2008: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.20158     

Facile syntheses of 4‐vinyl‐1,2,3‐triazole monomers by click azide/acetylene coupling

Synthetic strategies for the preparation of a new family of vinyl monomers, 4‐vinyl‐1,2,3‐triazoles, have been developed. These monomers are noteworthy as they combine the stability and aromaticity of styrenics with the polarity of vinylpyridines and the structural versatility of acrylate/methacrylate derivatives. To enable the wide adoption of these unique monomers, new methodologies for their synthesis have been elaborated which rely on Cu‐catalyzed azide/acetylene cycloaddition reactions—“click chemistry”—as the key step, with the vinyl substituent being formed by either elimination or Wittig‐type reactions. In addition, one‐pot “click” reactions have been developed from alkyl halides, which allow for monomer synthesis without isolation of the intermediate organic azides. The high yield and facile nature of these procedures has allowed a library of new monomers including the parent compound, 1‐H‐4‐vinyl‐1,2,3‐triazole, to be prepared on large scales. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2897–2912, 2008     

Chalcogenation reactions of a stable ferrocenyldiphosphene: Formation of thia‐, selena‐, and telluradiphosphiranes

The reactions of TbtPPTbt (Tbt = 2,4,6‐tris[bis(trimethylsilyl)methyl]phenyl) with elemental sulfur and selenium in the presence of triethylamine resulted in the formation of the corresponding thia‐ and selenadiphosphiranes in 71% and 65%, respectively, whereas the tellurization reaction was unsuccessful probably due to the steric reason. On the other hand, treatment of TbtPPFc (Fc = ferrocenyl) with elemental sulfur, selenium, and tributylphosphine telluride afforded the corresponding thia‐, selena‐, and telluradiphosphiranes in 84%, 88%, and 66% yields, respectively. The molecular structures of these three‐membered heterocyclic compounds were confirmed by spectroscopic analysis. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:443–449, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20449     

Synthesis of new functionalized aryl‐substituted methylphosphonic and methylenediphosphonic acids and their derivatives

The convenient syntheses of new aryl‐substituted hydroxymethylphosphonic and methylenediphosphonic acids from the aromatic aldehydes, their derivatives, and phosphorous acid esters in the presence of the effective catalysts (trimethylsilyl trifluoromethanesulfonate, zinc chloride, and cadmium iodide) were developed.