Facile synthesis of graft copolymers containing rigid poly(dialkyl fumarate) branches by macromonomer method

Graft copolymers show microphase separated structure as seen in block copolymers and have lower intrinsic viscosity than block copolymers because of a branching structure. Therefore, considering molding processability, especially for polymers containing rigid segments, graft copolymers are useful architectures. In this work, graft copolymers containing rigid poly(diisopropyl fumarate) (PDiPF) branches were synthesized by full free‐radical polymerization process. First, synthesis of PDiPF macromonomers by addition‐fragmentation chain transfer (AFCT) was investigated. 2,2‐Dimethyl‐4‐methylene‐pentanedioic acid dimethyl ester was found to be an efficient AFCT agent for diisopropyl fumarate (DiPF) polymerization because of the suppression of undesired primary radical termination, which significantly took place when common AFCT agent, methyl 2‐(bromomethyl)acrylate, was used. Copolymerization of PDiPF macromonomer with ethyl acrylate accomplished the generation of the graft copolymer having flexible poly(ethyl acrylate) backbone and rigid PDiPF branches. The graft copolymer showed a microphase separated structure, high transparency, and characteristic thermal properties to PDiPF and poly(ethyl acrylate). © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2474–2480     

Synthesis of transparent block copolymers consisting of poly(diisopropyl fumarate) and poly(2-ethylhexyl acrylate) segments by reversible addition-fragmentation chain transfer polymerization using trithiocarbonates as the chain transfer agents

The reversible addition-fragmentation chain transfer polymerization of diisopropyl fumarate (DiPF) was carried out using ethyl 2-[[(dodecylthio)thioxymethyl]thio]-2-methylpropionate (T1) and 1,1′-(1,2-ethanediyl) bis[2-[[(dodecylthio)thioxymethyl]thio]-2-methylpropionate] (T2) as the monofunctional and difunctional chain transfer agents (CTAs) to synthesize poly(diisopropyl fumarate) (PDiPF) with a rigid chain conformation. The obtained PDiPF had a well-controlled molecular weight, molecular weight distribution, and structure of the chain ends. Size exclusion chromatography and NMR measurements revealed an excellent introduction efficiency (84–98%) of the terminal trithiocarbonate group into the polymer chain end. They were available as the monofunctional and difunctional macro-CTAs to synthesize the AB and ABA block copolymers, respectively. While the well-controlled block copolymers were solely obtained by the polymerization of 2-ethylhexyl acrylate as the second monomer in the presence of PDiPF as the macro-CTA, the block copolymerization of DiPF using poly(2-ethylhexyl acrylate) as the macro-CTA failed. The trithiocarbonate group at the chain end was completely removed by the reaction with n-butylamine and it was valid for the improvement of the coloration and other optical properties of the transparent polymers. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2584–2594     

PHOSPHORORGANISCHE VERBINDUNGEN 921

Abstract

Optisch aktive Phosphinigsäureamide R¹R²PNR₂ 4 (R¹ [dbnd] Ph, R² [dbnd] Me bzw. Et, R [dbnd] Et) sind durch kathodische Spaltung bzw.Cyanolyse optisch aktiver Amidophosphoniumsalze [R¹R²R³PNR₂]X (R¹ [dbnd] Ph. R² [dbnd] Me bzw. Et. R³ [dbnd] Bz bzw. All, R [dbnd] Et) unter Erhaltung der Konfiguration in hohen Ausbeuten zugänglich.

Optisch aktive Amidophosphoniumverbindungen, z.B. Ethyl-methyl-phenyl-diethylamido-phosphoniumiodid 10 oder Benzyl-ethyl-phenyl-diethylamido-phosphoniumbromid 12 werden erhalten:

a) aus den optisch aktiven tertiären Phosphinen, z.B. R-(+)Benzyl-methyl-phenyl-phosphin 6 bzw. S-(-)Ethyl-methyl-phenyl-phosphin 13 durch Umsetzung mit Alkyl- oder Arylaziden über die Phosphinimine 7 mit anschließender Alkylierung.

b) durch Alkylierung der optisch aktiven Phosphinigsäureamide 4. Die unter a) und b) genannten Umsetzungen verlaufen unter Erhaltung der Konfiguration.

c) Bei der Umsetzung optisch aktiver tertiärer Phosphine mit N-Halogenaminen entstehen nur racemische Amidophosphoniumsalze.

Optisch aktive Amidophosphoniumsalze, z.B. S(+)-Benzyl-methyl-phenyl-diethylamido-phosphoniumbromid 8 oder R-(-)-Ethyl-methyl-phenyl-diethylamido-phosphoniumiodid 10 werden bei der Einwirkung wäßriger Alkalien unter Inversion zu den entsprechenden Phosphinoxiden 9 bzw. 11 abgebaut. Optisch aktive Amidophosphoniumsalze, z.B. S(+)-Benzyl-ethyl-phenyl-diethylamido-phosphoniumbromid 12, werden mit LiAlH₄ retentiv unter Abspaltung des Aminliganden in die zugrundeliegenden optisch aktiven tertiären Phosphine übergeführt. Die Olefinierung von Benzaldehyd mit S(+)-Benzyl-ethyl-phenyl-diethylamido-phosphoniumbromid 5 ergibt unter Retention Stilben und optisch aktives Ethyl-phenyl-phosphinsäure-diethylamid 17, das auch durch Oxidation von R(-)-4 mit H₂O₂ erhalten wird. Schwefelung von R(-)-4 liefert das optisch aktive Ethyl-phenyl-thiophosphinsäure-diethylamid 18.

Das optisch aktive Phosphinigsäure-diethylamid 4 racemisiert allein und in Kohlenwasserstoffen gelöst bei 130°C nach einer Reaktion nullter Ordnung. Die Racemisierung wird durch Austausch der sekundären Aminogruppe über cyclische Assoziate verursacht. Beweis: Verbindungen mit unterschiedlichen. Substituenten am Phosphor- und Stickstoff tauschen beim dreistündigen Erhitzen auf 200°C die sekundären Aminogruppen aus. Es entstehen neue Phosphinigsäureamide in annähernd äquivalenten Mengen.

In Nitrobenzol bildet sich mit Phosphinigsäureamiden ein Charge-Transfer-Komplex, der im Falle des optisch aktiven Ethyl-phenyl-phosphinigsäure-diethylamids 4 bereits bei Zimmertemperatur eine schnelle Racemisierung bewirkt.

Optisch aktives Ethyl-phenyl-phosphinigsäure-diethylamid 4 liefert als Co-Katalysator bei der Homogenhydrierung von α-Ethylstyrol mit (RhCl-Hexadien-1,5)₂ 2-Phenylbutan mit einer optischen Ausbeute von 34%.     

Microwave-Assisted Synthesis of Quinoxalines,Benzoxazines, and Benzothiazines Under Solvent-Free Conditions

The addition of dialkyl acetylenedicarboxylate to o-phenylenediamine, o-aminophenol, and o-aminothiophenol under microwave irradiation in solventless system rapidly afforded quinoxaline, benzoxazine, and benzothiazine derivatives, respectively.     

Multicomponent one-pot synthesis of (dihydro-1H-benzo[d]imidazole) phosphonate

Abstract

We present a multicomponent reaction strategy to synthesize a (dihydro-1H-benzo[d]imidazole)phosphonate family of compounds, using benzimidazoles, diethyl chlorophosphate and aliphatic amines as starting reactants. Giving its simplicity, our procedure involves reaction times of only few hours and avoid the usage of any catalyst agent. All the newly synthesized compounds were characterized by Nuclear Magnetic Resonance spectroscopy (¹H, ¹³C and ³¹P) and mass spectrometry by the DART method.     

An Efficient,One-Pot Synthesis of Dialkyl 5-Hydroxy-4-aryl-2,5-dihydrofuran-2,3-dicarboxylate Derivatives

The reaction between arylglyoxalmonohydrates, dialkyl acetylenedicarboxylates, and triphenylphosphine is described as a simple and efficient method for the synthesis of 5-hydroxy-4-aryl-2,5-dihydrofuran-2,3-dicarboxylate derivatives.     

Synthesis of Dialkyl 2‐(Alkylamino)‐4,9‐dihydro‐9‐oxocyclohepta[b]pyran‐3,4‐dicarboxylates

Dialkyl 2‐(alkylamino)‐4,9‐dihydro‐9‐oxocyclohepta[b]pyran‐3,4‐dicarboxylates are prepared in a one‐pot three‐component reaction of alkyl isocyanide, dialkyl acetylenedicarboxylate, and α‐tropolone (=2‐hydroxycyclohepta‐2,4,6‐trienone). The reaction proceeds smoothly at room temperature and under neutral conditions to afford tropolone derivatives in high yield.     

合成磷酰氯二烷基酯的新方法

以亚磷酸三烷基酯为原料,三氯异氰尿酸为氯代试剂,二氯甲烷为溶剂,在室温下合成了磷酰氯二烷基酯,其结构经1H NMR, 31P NMR和GC-MS确证.     

Synthesis of Alkyl (5-Oxo-2-thioxo-[1,3,4]thiadiazinan-6-ylidene)acetates by the Reaction of N-Aminorhodanine,Dialkyl Acetylenedicarboxylates,and Triphenylphosphine

Protonation of the reactive zwitterionic intermediate produced from the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates by N-aminorhodanine followed by the addition of the conjugate anion of N-aminorhodanine on the produced vinylphosphonium cation leads to alkyl (5-oxo-2-thioxo-[1,3,4]thiadiazinan-6-ylidene)acetates in good yields.