Derivatives of cis-NPCl2(NSOCl)2 and (NPCl2)2NSOCl. Part XIV—synthesis and nuclear magnetic resonance study of dimethylamino derivatives of NPCl2(NSOPh)2 and (NPCl2)2NSOPh

The compounds trans-NPCl_2?n(NMe₂)_n(NSOPh)₂(n=0-2iNPCl_2?n NMe₂)_n (NSOPh)₂ (n=0-2) and N₂P₂Cl_4?nl_4?n(NMe₂)_nNSOP₂P₂Cl_4?n(NMe₂)_nNSOPh(n=0-4), were prepared from their chloro-precursors. The substitution follows a completely non-geminal pathway, and all possible isomers are formed. The observed relative abundance of these isomers shows that the phenyl group exhibits a strong directing effect on the incoming amine. The ¹H, ³¹P and ¹³C NMR spectra of the most abundant isomers are reported. ²J(CP) couplings within the PNMe₂ grouping are affected by the number of substituents at the phosphorus atom. Almost linear relationships exist between the degree of substitution and the chemical shift of C-1 and C-4 of the phenyl groups. The effect of substitution on the ¹³C chemical shifts of these groups is ascribed to inductive effects.     

Spectroscopic and theoretical studies of N-trichlorophosphazotrifluoroacetyl,CF3C(O)NPCl3 and N-trichlorophosphazotrichloroacetyl,CCl3C(O)NPCl3

FTIR, Raman and NMR spectra of N-trichlorophosphazotrifluoroacetyl, CF₃C(O)NPCl₃ (1) and N-trichlorophosphazotrichloroacetyl, CCl₃C(O)NPCl₃ (2) were obtained. The experimental data are compared with results of ab initio and density functional theory (DFT) calculations. According the theoretical studies the main conformer for both molecules possesses C_s symmetry (CO bond syn respect to the NP bond). The preference of the syn conformation has been rationalized based on the natural bond orbital formalism. The vibrational spectra of 1 in the liquid phase and 2 in the solid phase are in good agreement with theoretical results.     

Polycondensation of bis(p-nitrophenyl) β-truxinate with diamine

Model reaction of bis(4-nitrophenyl) β-truxinate (BNPT) with aliphatic amines proceeded quantitatively at room temperature. Accordingly, polycondensation of BNPT with various diamines was carried out at room temperature or 80°C. During the polycondensation of BNPT with diamines, the precipitation of polymer or the observed gelation of polymerization solution occurred, which may limit the molecular weight of the polymer. On the other hand, the reaction of BNPT with 1,3-(4-piperidyl)propane (DPP) proceeded homogeneously to give the polymer with relatively high molecular weight, and the obtained polyamide (P-1e) showed excellent solubility in many solvents. The study of TG and DTA indicated that the obtained polymers were stable at lower temperature than around 270°C. The polymer prepared from the polycondensation of BNPT with hexamethylenediamine showed melting point and decomposition due to the imidation at 282°C. The photochemical reaction of these polymers was carried out in the film state. The irradiation of 254 nm light caused an absorption at 272 nm to appear and the molecular weight to decrease. This meant that the scission of cyclobutane ring in the main chain occurred to give cinnamamide structures. Also, the absorption at 272 nm decreased by the irradiation of 302.5 nm light. However, the UV spectrum of irradiated polymer did not agree with that of the original polymer. These results suggested that the dimerization of the resulting cinnamamide moieties occurred in the competition of their trans–cis-isomerization. On the other hand, the rate of scission of cyclobutane ring of P-1e was faster than that of the corresponding polyamide containing α-truxillamide structure.     

Alkyliminophosphorsäuretrihalogenide, 1. Mitt.: Halogenaustausch zwischen (CH3NPCl3)2 und (CH3NPF3)2

Zusammenfassung Durch Reaktion von dimerem Methyliminophosphorsäuretrichlorid mit dimerem Methyliminophosphorsäuretrifluorid werden die gemischt halogenierten dimeren Methyliminophosphorsäuretrihalogenide der allgemeinen Zusammensetzung (CH₃NP)₂Cl _n F_6–n mitn=1–5 dargestellt. Die analytischen Daten und die IR-Spektren werden mitgeteilt.

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Alkylimino phosphoric acid trihalogenides, I.: Halogen exchange between (CH₃NPCl₃)₂ and (CH₃NPF₃)₂

The reaction of (CH₃NPCl₃)₂ and (CH₃NPF₃)₂ yields the unknown 1.3-diaza-2.4-fluorochloro-phosphetidines of the general formula (CH₃NP)₂Cl _n F_6–n withn=1–5. The synthesis, the analytical data and the IR-spectra are reported.

     

Stable and Storable N(CF3)2 Transfer Reagents

Fluorinated groups are essential for drug design, agrochemicals, and materials science. The bis(trifluoromethyl)amino group is an example of a stable group that has a high potential. While the number of molecules containing perfluoroalkyl, perfluoroalkoxy, and other fluorinated groups is steadily increasing, examples with the N(CF₃)₂ group are rare. One reason is that transfer reagents are scarce and metal-based storable reagents are unknown. Herein, a set of Cu^I and Ag^I bis(trifluoromethyl)amido complexes stabilized by N- and P-donor ligands with unprecedented stability are presented. The complexes are stable solids that can even be manipulated in air for a short time. They are bis(trifluoromethyl)amination reagents as shown by nucleophilic substitution and Sandmeyer reactions. In addition to a series of benzylbis(trifluoromethyl)amines, 2-bis(trifluoromethyl)amino acetate was obtained, which, upon hydrolysis, gives the fluorinated amino acid N,N-bis(trifluoromethyl)glycine.     

Photochemical Oximesulfonylation of Alkenes Using Sulfonyl-Oxime-Ethers as Bifunctional Reagents

Utilization of oxime ethers as bifunctional reagents remains unknown. Herein, we present a mechanistically distinct strategy that enables oximesulfonylation of olefins using sulfonyl-oxime-ethers as bifunctional reagents under metal-free photochemical conditions. Via concomitant C−S and C−C bond formation, the process permits incorporation of oxime and sulfonyl groups into olefins in a complete atom-economic fashion, providing rapid access to multi-functionalized β-sulfonyl oxime ethers with good yields and stereoselectivity. The method is amenable to functionalization of complex bioactive molecules and is shown to be scalable. A radical chain mechanism initiated via photochemical Hydrogen Atom Transfer (HAT) mediated N−O bond cleavage is suggested for the process, based on our results on mechanistic investigations.     

1,3-Dipolar Cycloaddition of Dipolar Reagents to Bifunctional Olefins with Chloramine-T --- Part-II

A one pot synthesis of pyrazoles and isoxazoles was achieved by 1,3-dipolar cycloaddition of nitrile imines and nitrile oxides to an activated olefins in the presence of chloramine-T.     

硫代磷酰基硫脲与某些含氯双官能团试剂的成环反应

Ｏ－乙基－Ｎ－异丙基硫代磷酰硫脲衍生物与氯乙酰氯、二氯乙酰氯及三氯乙酰氯，在碱存在下可发生关环反应，得到相应的噻唑啉酮类衍生物，讨论了不同试剂及反应条件对产物结构的影响，而Ｏ－乙基－Ｎ－异丙基硫代磷酰硫脲与氯乙醛关环，则生成相应的噻唑衍生物，所有化合物经元素分析、＾１ＨＮＭＲ、ＩＲ及ＭＳ证实，其中部分化合物显示出一定的除草活性。     

Photochemical Carbopyridylation of Alkenes Using N-Alkenoxypyridinium Salts as Bifunctional Reagents

N-Alkenoxypyridinium salts have been used as synthons for the umpolung reaction of enolates for the preparation of α-functionalized carbonyl compounds. In contrast, we found that the photoreduction of N-alkenoxypyridinium salts generates α-carbonyl radicals after cleavage of the N−O bond, thereby allowing simultaneous incorporation of α-keto and pyridyl groups across unactivated alkenes. In the process, the formed α-carbonyl radicals engage unactivated alkenes to afford alkyl radical intermediates poised for subsequent addition to pyridinium salts, which ultimately affords a variety of γ-pyridyl ketones under mild reaction conditions. This transformation is characterized by a broad substrate scope and good functional-group compatibility, and the utility of this transformation was further demonstrated by the late-stage functionalization of complex biorelevant molecules.     

Poly(siloxaneimide)s 2. Polycondensation of some imidic diacid chlorides with aminoalkylsiloxanes

Some new poly(siloxaneimide) copolymers with good solubilities have been synthesized by solution polycondensation of aromatic diacid chlorides containing preformed imide rings with disiloxanes and siloxane oligomers having α,ω-aminopropyl functionalities. The polycondensation reactions were carried out using equimolecular amounts of the two monomers, in polar aprotic solvents and inert atmosphere.The obtained compounds were characterized by elemental C, H, and Si analysis, solubility measurements, IR and 1H-NMR spectrometry. Thermogravimetric curves were also recorded. All data agree with the proposed structures.     

Polycondensation of Tris(Trimethylsilylseleno)Phosphane

Abstract

Tris-(trimethylsilyl)phosphane and their organo substituted derivatives (Me₃Si)_3?nP(Me₃C)_n (n: 0, 1, 2) (la-c) had been found suitable for the insertion of selenium into the phosphorus-silicon bond. At deep temperatures all silylselenophosphanes of the series (Me₃SiSe)_3?nP(Me₃C_n) (2a-c) are formed in a nearly quantitative reaction, if no excess selenium is present. (Me₃C)(Me₃SiSe)₂P=Se (3b) and (Me₃C)₂(Me₃SiSe)P=Se (3c) are detectable in small quantities as the only by-products of the reaction of (Ib-c), whereas (la) end in the formation of (2a) and traces of the dimer (Me₃SiSe)₂P-P(SeSiMe₃)₂ (4). On exposure to light or at elevated temperatures (2a) undergoes a disproportionation, forming Se=P(SeSiMe₃)₃ (3a), and the heterocycles P₃Se₄(SeSiMe₃) (5) and α-P₄Se₃(SeSiMe₃)₂ (6). (Me₃Si)₂Se is spUt off as a condensation product. After further irradiation or prolonged standing at room temperature, an insoluble oligomer is formed. The constitutions of (2-6) were determined by the analysis of their ³¹P- and ⁷⁷Se-nmr spectra.     

Direct Transformation of Esters into Arenes with 1,5‐Bifunctional Organomagnesium Reagents

A direct transformation of carboxylic acid esters into arenes with 1,5‐bifunctional organomagnesium reagents is described. This efficient and practical method enables the one‐step defunctionalization of various carboxylic acid esters to prepare benzene, anthracene, tetracene, and pentacene derivatives. A double nucleophilic addition of the 1,5‐organodimagnesium reagent to the ester is followed by an immediate 1,4‐elimination reaction that leads to the direct [5+1] formation of a new aromatic ring.     

Über die Reaktion von CH3N(PCl3)(BCl3) und [(CH3)2NPCl3] [BCl4] mit AsF3

Products of the reaction between CH₃N(PCl₃)(BCl₃) and AsF₃ are BF₃, AsCl₃ and N,N′-dimethyldiazafluorophosphetidine IV. [(CH₃)₂NPCl₃][BCl₄] reacts with AsF₃ to give dimethylaminotetrafluorophosphorane VI. Preparation and NMR data of IV and VI are given.     

Mechanism of the controlled hydrolysis of (NPCl2)2NSOCl: Crystal and molecular structure of [KC12H24O6]+[NHPO2NPCl2NSOCl]−

The reaction mechanism of controlled hydrolysis of the inorganic ring system (NPCl₂)₂NSOCl in the presence of KCl and 18-crown-6 has been revised and is explained from steric constraints rather than from electronic considerations. The X-ray structure of one of the hydrolysis products, [KC₁₂H₂₄O₆]⁺-[NHPO₂NPCl₂NSOCl]⁻, shows a dimeric structure of two centrosymmetrically related formula units kept together by hydrogen bridges and K … O coordination. Crystals are monoclinic, space group C2/c with a = 25.698(5), b = 8.223(2), c = 23.665(4) Å, β = 106.03(1)°, V = 4806(2) ų, and Z = 8. The final R and R_w values are 0.048 and 0.044, respectively.     

Reaction of [3-(Dimethylamino)-2-Azaprop-2-en-1-Ylidene] Dimethylammonium Chloride with Grignard Reagents

Abstract

We recently reported¹ that [3-(Dimethylamino)-2-azaprop-2-en-1-ylidene] dimethylammonium chloride² (1) could be reacted with anions derived from ketones or amides to produce enaminones or acylamidines, respectively.     

Microwave-assisted Polycondensation of L-2-Hydroxy-3-phenylpropanoic Acid

The attempts to prepare novel biodegradable polymer carriers for drug controlled release systems have been tried in our group1,2. Poly (L-2-hydroxy-3-phenylpropanoic acid) (PLHPPA) can be considered as derivative of poly (lactic acid) (PLA) which has been applied as biomaterials in drug delivery systems, surgical repair and tissue engineering materials3 for its excellent biodegradability and biocompatibility. PLHPPA contains phenyl groups in its structure. It is designed as a hydrophobic…