- The Formation of P-C Bonds Utilizing Organozinc Reagents for the Synthesis of Aryl- A nd Heteroaryl-Dichlorophosphines
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Aryl- A nd heteroaryl-dichlorophosphines are mildly and selectively made in a one-pot synthesis in moderate to good yields starting from the respective aryl bromides or five-membered heterocycles, following lithiation with nBuLi, transmetalation with ZnCl
- Kirst, Christin,Tietze, Jonathan,Ebeling, Marian,Horndasch, Lukas,Karaghiosoff, Konstantin
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p. 17337 - 17343
(2021/11/18)
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- AlCl3-catalyzed C-H p hosphination of benzene: A mechanistic study
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The characteristics of the reaction for the preparation of dichlorophenylphosphine (DCPP) via benzene and PCl3 in the presence of AlCl3 were studied. Some unique characteristics were observed when a catalytic amount of AlCl3 was used. Namely, more than one mole of DCPP was obtained per mole AlCl3, the reaction solution was layered, and DCPP could be directly separated. Our mechanistic study showed that benzene reacted with PCl3 to form DCPP-AlCl3, and DCPP-AlCl3 dissociated into DCPP and AlCl3, continuing to catalyze this reaction. This resulted in the high catalytic efficiency of AlCl3. The layering of the reaction solution was caused by the immiscibility of DCPP-AlCl3 with the raw materials, greatly facilitating the dissociation process of DCPP-AlCl3. The formation of diphenylphosphorus chloride (DPC) was due to a continuous Friedel-Crafts reaction between DCPP and benzene. DPC cooperated with AlCl3 to form the stable coordination compound DPC-AlCl3 that did not dissociate and was responsible for the deactivation of AlCl3.
- Duan, Haodong,Gao, Jun,Guo, Ge,Han, Yuxi,Leng, Kangwei,Li, Xinjin,Wang, Zhongwei,Xu, Xiaolei,Yu, Qing
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- Bicyclic heterocycles, the preparation thereof, and their use as pharmaceuticals
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The present invention relates to 5-membered heterocyclic condensed benzoderivatives of formula wherein Ra to Rc, A, X and Y are defined as in claim 1, the tautomers, stereoisomers, mixtures thereof and the salts thereof, particularly the physiologically acceptable salts thereof with inorganic or organic acids or bases which have valuable properties. The compounds of the above formula I wherein Rc denotes a cyano group are valuable intermediates for preparing the other compounds of formula I, and the compounds of the above formula I wherein Rc denotes one of the following amidino groups and the tautomers and stereoisomers thereof have valuable pharmacological properties, particularly an antithrombotic activity.
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- Process for preparing organic chlorophosphanes
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Organic chlorophosphanes of the formula III STR1 in which R1 is chlorine or an aliphatic radical, preferably only chlorine, and R2 is an aromatic, heterocyclic or aliphatic radical, are prepared by reacting organic phosphorus oxychlorides of the formula I STR2 in which R1 is chlorine or an aliphatic radical, preferably only chlorine, R2 is an aromatic or heterocyclic radical in the event that R1 is chlorine and an aromatic, heterocyclic or aliphatic radical in the event that R1 is an aliphatic radical, with a trialkylphosphane of the formula II in which R3 is an aliphatic radical, at temperatures between about 20° and about 170° C. Said organic chlorophosphanes III are mainly intermediates in various fields, such as pharmaceuticals, plant protection, dyestuffs and polymers.
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- DIARYLPHOSPHINIC AZIDES. PHOTOCHEMICAL REACTIONS INCLUDING REARRANGEMENT IN METHANOL
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On photolysis in methanol the diarylphosphinic azides Ar2P(O)N3 (Ar=phenyl, p-tolyl, p-anisyl, p-chlorophenyl) rearrange with loss of nitrogen to form (monomeric) metaphosphonimidates which are trapped by the solvent to give methyl NP-diarylphosphonamidates (7) (41-53percent).Diarylphosphinic amides (18-42percent) are also usually formed, presumably from (triplet) nitrenes.The limited evidence available suggests that the rearrangements take place directly from the photo-excited azides rather than via (singlet) nitrene intermediates.One of the products of rearrangement, methyl NP-di(p-chlorophenyl)phosphonamidate, suffers extensive photochemical dechlorination giving methyl N-phenyl-P-p-chlorophenylphosphonamidate.
- Harger, Martin J.P.,Westlake, Sally
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p. 1511 - 1516
(2007/10/02)
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