A practical and cheap method for synthesis of C-4 carboxylic acid substituted kainic acid analogue 5 and its epimer 6 from trans-4-hydroxyproline is described. Using this method, more interesting intermediates and ana...A practical and cheap method for synthesis of C-4 carboxylic acid substituted kainic acid analogue 5 and its epimer 6 from trans-4-hydroxyproline is described. Using this method, more interesting intermediates and analogues could be obtained easily.展开更多
Synthesis of 11C-labeled capsaicin ([11C]-2) was accomplished by O-[11C]methylation with [11C]-methyl iodide to a corresponding catechol precursor (1). In Vivo whole-body distribution of [11C]-2 in rats was investigat...Synthesis of 11C-labeled capsaicin ([11C]-2) was accomplished by O-[11C]methylation with [11C]-methyl iodide to a corresponding catechol precursor (1). In Vivo whole-body distribution of [11C]-2 in rats was investigated by positron emission tomography after intravenous injection. The results showed that [11C]-2 accumulated in the brain and body surface, which was closely associated with the expression of transient receptor potential vanilloid 1.展开更多
The use of thallium(I) hydroxide (TlOH) as a base is known to extremely accelerate the Suzuki-Miyaura cross-coupling reaction using organoboronic acid or organoboronic acid ester as a substrate. Here, we investigated ...The use of thallium(I) hydroxide (TlOH) as a base is known to extremely accelerate the Suzuki-Miyaura cross-coupling reaction using organoboronic acid or organoboronic acid ester as a substrate. Here, we investigated the effects of TlOH by comparing with other conventional bases such as KOH, K2CO3, and CsF for Pd0-mediated rapid cross-coupling reactions between CH3I and organoborane reagents, such as phenyl-, (Z)-4-benzyloxy-2-butenyl-, and benzylboronic acid pinacol esters under the conditions CH3I/borane/Pd0/base (1:40:1:3) in THF/H2O or DMF/H2O for 5 min with an aim to fabricate a PET tracer efficiently. Consequently, however, the use of TlOH was much less efficient than the other bases for the acceleration of cross-coupling reactions. Thus, it was reconfirmed that the milder and non-toxic conditions using K2CO3 or CsF so far developed by our group were most appropriate for the rapid C-methylations.展开更多
11C-labeled C1-C10 partial structure of kulokekahilide-2 (1) was successfully synthesized based on Pd0-mediated rapid C-[11C]methylation using [11C]methyl iodide and pinacol alkenylboronate. The preparation of organob...11C-labeled C1-C10 partial structure of kulokekahilide-2 (1) was successfully synthesized based on Pd0-mediated rapid C-[11C]methylation using [11C]methyl iodide and pinacol alkenylboronate. The preparation of organoboron intermediate via olefin cross-metathesis is also a crucial procedure for the synthesis of 11C-labeling C1-C10 dihy-droxy acid moiety of 1.展开更多
Updating the velocity in particle swarm optimization (PSO) consists of three terms: the inertia term, the cognitive term and the social term. The balance of these terms determines the balance of the global and local s...Updating the velocity in particle swarm optimization (PSO) consists of three terms: the inertia term, the cognitive term and the social term. The balance of these terms determines the balance of the global and local search abilities, and therefore the performance of PSO. In this work, an adaptive parallel PSO algorithm, which is based on the dynamic exchange of control parameters between adjacent swarms, has been developed. The proposed PSO algorithm enables us to adaptively optimize inertia factors, learning factors and swarm activity. By performing simulations of a search for the global minimum of a benchmark multimodal function, we have found that the proposed PSO successfully provides appropriate control parameter values, and thus good global optimization performance.展开更多
A partial order on the set of the prime knots can be defined by the existence of a surjective homomorphism between knot groups. In the previous paper, we determined the partial order in the knot table. In this paper, ...A partial order on the set of the prime knots can be defined by the existence of a surjective homomorphism between knot groups. In the previous paper, we determined the partial order in the knot table. In this paper, we prove that 31 and 41 are minimal elements. Further, we study which surjection a pair of a periodic knot and its quotient knot induces, and which surjection a degree one map can induce.展开更多
文摘A practical and cheap method for synthesis of C-4 carboxylic acid substituted kainic acid analogue 5 and its epimer 6 from trans-4-hydroxyproline is described. Using this method, more interesting intermediates and analogues could be obtained easily.
文摘Synthesis of 11C-labeled capsaicin ([11C]-2) was accomplished by O-[11C]methylation with [11C]-methyl iodide to a corresponding catechol precursor (1). In Vivo whole-body distribution of [11C]-2 in rats was investigated by positron emission tomography after intravenous injection. The results showed that [11C]-2 accumulated in the brain and body surface, which was closely associated with the expression of transient receptor potential vanilloid 1.
文摘The use of thallium(I) hydroxide (TlOH) as a base is known to extremely accelerate the Suzuki-Miyaura cross-coupling reaction using organoboronic acid or organoboronic acid ester as a substrate. Here, we investigated the effects of TlOH by comparing with other conventional bases such as KOH, K2CO3, and CsF for Pd0-mediated rapid cross-coupling reactions between CH3I and organoborane reagents, such as phenyl-, (Z)-4-benzyloxy-2-butenyl-, and benzylboronic acid pinacol esters under the conditions CH3I/borane/Pd0/base (1:40:1:3) in THF/H2O or DMF/H2O for 5 min with an aim to fabricate a PET tracer efficiently. Consequently, however, the use of TlOH was much less efficient than the other bases for the acceleration of cross-coupling reactions. Thus, it was reconfirmed that the milder and non-toxic conditions using K2CO3 or CsF so far developed by our group were most appropriate for the rapid C-methylations.
文摘11C-labeled C1-C10 partial structure of kulokekahilide-2 (1) was successfully synthesized based on Pd0-mediated rapid C-[11C]methylation using [11C]methyl iodide and pinacol alkenylboronate. The preparation of organoboron intermediate via olefin cross-metathesis is also a crucial procedure for the synthesis of 11C-labeling C1-C10 dihy-droxy acid moiety of 1.
文摘Updating the velocity in particle swarm optimization (PSO) consists of three terms: the inertia term, the cognitive term and the social term. The balance of these terms determines the balance of the global and local search abilities, and therefore the performance of PSO. In this work, an adaptive parallel PSO algorithm, which is based on the dynamic exchange of control parameters between adjacent swarms, has been developed. The proposed PSO algorithm enables us to adaptively optimize inertia factors, learning factors and swarm activity. By performing simulations of a search for the global minimum of a benchmark multimodal function, we have found that the proposed PSO successfully provides appropriate control parameter values, and thus good global optimization performance.
基金Grand-in-Aid for Scientific Research (No.17540064 and No.18840008)
文摘A partial order on the set of the prime knots can be defined by the existence of a surjective homomorphism between knot groups. In the previous paper, we determined the partial order in the knot table. In this paper, we prove that 31 and 41 are minimal elements. Further, we study which surjection a pair of a periodic knot and its quotient knot induces, and which surjection a degree one map can induce.
