Build your own closed loop: Graph-based proof of concept in closed loop for autonomous networks

Next Generation Networks (NGNs) are expected to handle heterogeneous technologies, services, verticals and devices of increasing complexity. It is essential to fathom an innovative approach to automatically and efficiently manage NGNs to deliver an adequate end-to-end Quality of Experience (QoE) while reducing operational expenses. An Autonomous Network (AN) using a closed loop can self-monitor, self-evaluate and self-heal, making it a potential solution for managing the NGN dynamically. This study describes the major results of building a closed-loop Proof of Concept (PoC) for various AN use cases organized by the International Telecommunication Union Focus Group on Autonomous Networks (ITU FG-AN). The scope of this PoC includes the representation of closed-loop use cases in a graph format, the development of evolution/exploration mechanisms to create new closed loops based on the graph representations, and the implementation of a reference orchestrator to demonstrate the parsing and validation of the closed loops. The main conclusions and future directions are summarized here, including observations and limitations of the PoC

Synthesis and structures of cis- and trans-bis(allenyl)cylclodiphosph(V)azanes and a bis(allyl)cyclodiphosph(V)azane

The bis-(allenyl)phosphoramidates cis-[(H2C=C=CH)(O)P(μ-N-t-Bu)]2 (9), cis- and trans-[(Me2C=C=CH)(O)P(μ-N-t-Bu)]2 (10a,b) and cis- and trans-[((Me)(Et)C=C=CH)(O)P(μ-N-t-Bu)]2 (11a,b) based on a cyclodiphosph(V)azane skeleton have been synthesized by treating cis-[ClP(μ-N-t-Bu)]2 (1) with the respective propargylic alcohol in the presence of triethylamine. The Baylis-Hillman adduct PhCH(OH)C(CO2Me)=CH2 also reacts with 1 to lead to the bis-(allyl)phosphoramidate cis-[((Ph)HC=C(CO2Me)-CH2)(O)P(μ-N-t-Bu)]2 . H2O (13 . H2O). In this case, a 31P NMR study shows that yet another P(V) compound, tentatively assigned the trans-structure, was initially formed. Preliminary calculations suggest that the cis-isomer 10a is slightly more stable than the trans-isomer 10b in the gas phase. The structures of 9, 10a,b and 13 . H2O are confirmed by X-ray crystallography

Photoassisted Diversity-Oriented Synthesis: Intramolecular Cycloadditions of Photogenerated Azaxylylenes with Oxazole Pendants, and Subsequent Postphotochemical Multicomponent Modifications

Photogenerated aza-<i>o</i>-xylylenes undergo intramolecular cycloaddition reactions to tethered oxazoles, with primary photoproducts featuring a reactive cyclic imine moiety suitable for multicomponent postphotochemical transformations. For example, the reaction of these imine photoproducts with bromoacetyl bromide leads to a key 1,4-dielectrophilic synthon, offering access to diverse polyheterocyclic molecular architectures. This reaction sequence is accompanied by rapid growth complexity in a very few simple synthetic steps, and is in keeping with the philosophy of diversity-oriented synthesis (DOS)

Further characterization of Mitsunobu-type intermediates in the reaction of dialkyl azodicarboxylates with P(III) compounds

Structural characterization of compounds analogous to the proposed intermediates in the Mitsunobu esterification process is achieved by the combined use of NMR spectroscopy and X-ray diffractometric studies. The results show that compounds (t-BuNH)P(&#956;-N-t-Bu)2P[(N-t-Bu)(N-(CO2R)-N(H)(CO2R))] [R = Et (11), i-Pr (12)], obtained by treating [(t-Bu-NH)P-&#956;-N-t-Bu]2 (10) with diethylazodicarboxylate (DEAD) or diisopropylazodicarboxylate (DIAD), respectively, have a structure with the NH proton residing between the two nitrogen atoms ((P)N(t-Bu) and (P)N-N(CO2Et)); this is the tautomeric form of the expected betaine (t-BuNH)P(&#956;-N-t-Bu)2P+[(NH-t-Bu)(N-(CO2R)-N-(CO2R)]. Treatment of ClP(&#956;-N-t-Bu)2P[(N-t-Bu){N-(CO2-i-Pr)-N(H)(CO2-i-Pr)] (6) with 2,6-dicholorophenol affords (2,6-Cl2-C6H3-O)P(&#956;-N-t-Bu)2P+[(NH-t-Bu){N[(CO2i-Pr)(HNCO2i-Pr)]}](Cl-)(2,6-Cl2-C6H3-OH) (14) that has a structure similar to that of (CF3CH2O)P(&#956;-N-t-Bu)2P+[(NH-t-Bu){N[(CO2i-Pr)(HNCO2i-Pr)]}](Cl-) (13), but with an additional hydrogen bonded phenol. Both of these have the protonated betaine structure analogous to that of Ph3P+N(CO2R)NH(CO2R)(R'CO2)- (2) proposed in the Mitsunobu esterification. Two other compounds, (ArO)P(&#956;-N-t-Bu)2P+(NH-t-Bu){N(CO2i-Pr)(HNCO2i-Pr)}(Cl-) [Ar = 2,6-Me2C6H3O- (15) and 2-Me-6-t-Bu-C6H3-O- (16)], are also prepared by the same route. Although NMR tube reactions of 11 or 12 with tetrachlorocatechol, catechol, 2,2'-biphenol, and phenol revealed significant changes in the 31P NMR spectra, attempted isolation of these products was not successful. On the basis of 31P NMR spectra, the phosphonium salt structure (t-BuNH)P(&#956;-N-t-Bu)2P+[(HN-t-Bu){N-(CO2R)-N(H)(CO2R)](ArO-) is proposed for these. The weakly acidic propan-2-ol or water did not react with 11 or 12. Treatment of 12 with carboxylic acids/ p-toluenesulfonic acid gave the products (t-BuNH)P(&#956;-N-t-Bu)2P+[(HN-t-Bu){N-(CO2-i-Pr)-N(H)(CO2-i-Pr)](ArCO2-) [Ar = Ph (18), 4-Cl-C6H4CH2 (19), 4-Br-C6H4 (20), 4-NO2-C6H4 (21)] and (t-BuNH)P(&#956;-N-t-Bu)2P+[(HN-t-Bu){N-(CO2-i-Pr)-N(H)(CO2-i-Pr)](4-CH3-C6H4SO3-) (22) that have essentially the same structure as 2. Compound 18 has additional stabilization by hydrogen bonding, as revealed by X-ray structure determination. Finally it is shown that the in situ generated (t-BuNH)P(&#956;-N-t-Bu)2P+[(HN-t-Bu){N-(CO2Et)-N(H)(CO2Et)](4-NO2-C6H4CO2-) can also effect Mitsunobu esterification. A comparison of the Ph3P-DIAD system with the analogous synthetically useful Ph3P-dimethyl acetylenedicarboxylate (DMAD) system is made

Photoassisted Diversity-Oriented Synthesis: Intramolecular Cycloadditions of Photogenerated Azaxylylenes with Oxazole Pendants, and Subsequent Postphotochemical Multicomponent Modifications

Photogenerated aza-<i>o</i>-xylylenes undergo intramolecular cycloaddition reactions to tethered oxazoles, with primary photoproducts featuring a reactive cyclic imine moiety suitable for multicomponent postphotochemical transformations. For example, the reaction of these imine photoproducts with bromoacetyl bromide leads to a key 1,4-dielectrophilic synthon, offering access to diverse polyheterocyclic molecular architectures. This reaction sequence is accompanied by rapid growth complexity in a very few simple synthetic steps, and is in keeping with the philosophy of diversity-oriented synthesis (DOS)

Reactivity of allenylphosphonates toward salicylaldehydes and activated phenols: facile synthesis of chromenes and substituted butadienes

The reaction of salicylaldehydes with allenylphosphonates in the presence of a base leads to a variety of phosphono-chromenes and allylic phosphonates. Optimization of reaction conditions reveals that DBU (base) in DMSO (solvent) is the best combination in most cases, with DBU acting as an organocatalyst. PEG-400 also gave good results, but the yields were slightly lower than that in DMSO. Several of the key products have been characterized by single-crystal X-ray crystallography. Interconversion of E and Z isomers of phosphono-chromenes is demonstrated by 31P NMR spectroscopy. A novel P-C bond cleavage reaction of some of these chromenes leading to substituted enones is also reported. In a few cases, phenol addition products are also isolated. In order to probe the pathways in the latter reaction, allenylphosphonates have also been treated with activated phenols in the presence of base to selectively afford either allylic phosphonyl ethers or vinylic phosphonyl ethers depending on the substituents on the allenylphosphonate. Theoretical calculations were consistent with experimental results. Finally, utilization of allylic phosphonyl ether in the Horner-Wadsworth-Emmons reaction to afford substituted trans-1,3-butadiene in good yields is demonstrated

Mitsunobu and related reactions: advances and applications

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Exploring organic reactions using simple cyclodiphosphazanes

Phosphine-activated reactions of alkynes/alkenes/allenes as well as the Mitsunobu reaction involve a rich phosphorus chemistry. With the aid of simple cyclodiphosphazanes, characterization of many compounds analogous to the proposed intermediates in such reactions has been accomplished. Use of a cyclodiphosphazane in Pd-catalyzed N-arylation reactions is highlighted. Results on molecular non-stoichiometry in phosphorus compounds and on the use of chiral phosphorus systems are discussed. Synthesis of allenylphosphoramides involving a cyclodiphosphazane is also described. X-ray structures of the new compounds [(t-BuNH)(PhCH2CH(CN)CH2-)P(&#956;-N-t-Bu)2P(NH-t-Bu)]+[HCO3]- (13), [(t-BuNH)P(&#956;-N-t-Bu)2P(=N-t-Bu)-C(=CH2)CH(C6H4-4-Me)-P(O)(OCH2CMe2CH2O)] (18), [(i-PrNH)P(&#956;-N-t-Bu)2P(=N-i-Pr)-N(CO2-i-Pr)-NH(CO2-i-Pr)] (24), [(S)-(2-OH-1-C10H6-1'-C10H6-2'-O-P(O)(NH-t-Bu)2] (36) and [(t-BuNH)(O)P(&#956;-N-t-Bu)2P(O)(CH=C=CMe2)] (40) are also reported

Photoassisted Diversity-Oriented Synthesis: Accessing 2,6-Epoxyazocane (Oxamorphan) Cores

The modular synthesis of photoprecursors and their photoinduced cyclization into substituted 1-benzazocanes of two distinct topologies is described. The key step producing an extended polyheterocyclic system involves the photogeneration of azaxylylenes and their subsequent intramolecular cycloaddition with furan-containing pendants tethered either via the aniline nitrogen or through the carbonyl group containing arm. The primary photoproductssecondary or tertiary anilines which are not acylated at the nitrogen atomundergo facile acid-catalyzed or spontaneous ring-opening–ring-closing rearrangement to yield fused polyheterocyclic structures possessing a 2,6-epoxyazocane (or oxamorphan) core