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In evaluating the wind response of base-isolated buildings, it is important to consider not only along-wind load but also the across-wind and the torsional wind loads. It is also known that devices using lead or tin with creep potential can be considered unable to resist mean wind force. In this paper, a simple evaluation method for the wind response of base isolated buildings is proposed considering the combination of equivalent static wind loads with creep potential.

Potassium alkoxide was found to be a highly active catalyst for the nucleophilic trifluoromethylation of carbonyl compounds. The catalytic system was successfully applied to the reactions of both aldehydes and ketones, affording the corresponding trifluoromethylated products in high yields at low catalyst loadings (0.1–0.01 mol%) in several solvents, such as THF, toluene, and CH2Cl2. In addition, the potassium salt of a Ru(II) complex bearing an (S)-2,2′-bis[bis(3,5-dimethylphenyl)phosphinyl]-1,1′-binaphthalene [(S)-XylBINAP] ligand and two l-threoninate ligands, prepared in situ, catalyzed the enantioselective trifluoromethylation of aromatic aldehydes, although the ee values were not satisfactory (less than 20%).

3-Aryloxindole derivatives were synthesized through a Friedel–Crafts-type cyclization. The reaction was catalyzed by a trimethylsilyl tricyanopalladate complex generated in situ from trimethylsilyl cyanide and Pd(OAc)2. Wide varieties of diethyl phosphates derived from N-arylmandelamides were converted almost quantitatively into oxindoles. When N,N-dibenzylamide was used instead of an anilide substrate, a benzo-fused δ-lactam was obtained. An oxindole product was subjected to substitution reactions to afford 3,3-diaryloxindoles with two different aryl groups.

The [2+2] photocycloaddition of alkenyl-tethered 1H-pyrrolo[2,3-b]pyridine derivatives sensitized with 3',4'-dimethoxyacetophenone under irradiation by a high-pressure mercury lamp through Pyrex glass was dramatically accelerated by the addition of Lewis acids, preferably Mg(OTf)(2), to give the products stereoselectively in high yields. The reaction without a Lewis acid gave only small amounts of the [2+2] cycloaddition products. Conformational fixation of the substrates by coordination with a Lewis acid was presumed to facilitate the cycloaddition.

We successfully demonstrated that Friedel−Crafts‐type allylation of phenol derivatives and allylic phosphates is catalyzed by the AgTFA/trimethylsilyl cyanide (Me3SiCN) and Pd(OAc)2/Me3SiCN combined systems to afford the C‐allylated product in a highly regioselective manner. The corresponding silyl cyanometallates generated in situ are proposed to be the active catalytic species. Lewis acidity of the reversibly formed ion pairs is appropriately regulated for this reaction. The para‐allylated anisole and phenol derivatives are selectively obtained. The para‐substituted ones are converted to the ortho‐allylated products. The reactivity of the catalytic systems is strongly dependent on the electronic nature of both electrophile and nucleophile. Substitution of an aromatic ring on the allylic phosphate is essential for the reaction. Thus, the competitive reaction of a 1 : 1 mixture of cinnamyl and simple allyl phosphates affords only the cinnamyl‐substituted product.

Silver-catalysed benzylic isocyanation was achieved. When a readily available silver(I) compound, Ag2O, was employed as a catalyst in 1,4-dioxane, nucleophilic substitution of benzylic phosphates with trimethylsilyl cyanide (TMSCN) gave the less-stable benzylic isonitriles exclusively. No benzylic nitrile, which is the more stable regioisomer, was observed through the reaction. Notably, secondary benzylic isonitriles, which had not been available by catalytic substitutions, as well as primary ones were obtained in high yield. The selection of the leaving group of the benzylic electrophiles was crucially important, namely, the desired isonitriles were obtained in high yield only when the phosphates were used as substrates. A mechanistic study suggested that (TMS)[Ag(CN)2] formed in situ from the silver(I) salt and excess amounts of TMSCN functioned as an active species, and the substitution proceeded through an SN1-type process rather than in SN2 fashion.

In the presence of catalytic amount of Pd(OAc)2, allylic phosphates reacted with trimethylsilyl cyanide (TMSCN) to afford the corresponding allylic isonitriles exclusively. No allylic nitriles, which are selectively obtained in the traditional Pd(0)-catalyzed reaction, were observed. The use of phosphate as the leaving group was crucial to achieve complete regioselectivity of the ambident cyanide species as the N-terminus nucleophile. The reaction was applicable to a series of aromatic-, heteroaromatic-, vinylic-, and aliphatic-substituted allylic phosphates. The mechanistic studies suggested that the allylic isocyanation was catalyzed by the Pd(II) species, and not by Pd(0).

Two types of chiral Ru(II) complexes, each with two kinds of ligands, have been designed and utilized as catalysts for several asymmetric reactions under appropriate conditions. The first type, the...

Irradiation of 1-(hexa-4,5-dienoyl)indole derivatives in the presence of an aromatic ketone by a high-pressure mercury lamp through Pyrex glass gave the corresponding cyclized products stereoselectively in high yields. The major part of the products was an all- cis-fused methylenecyclobutane-type compound produced through [2+2] cycloaddition, accompanied by small amounts of alkynes via 1,5-hydrogen transfer of a biradical intermediate. Among a range of aromatic ketones, 3',4'-dimethoxyacetophenone was found to sensitize the substrate quite effectively.

The DIPSkewphos/PICA derivative-Ru(II) complexes catalyzed asymmetric hydrogenation of significantly sterically hindered 2',3',4',5',6'-pentamethylacetophenone, which was not reduced with NaBH4 at 25 degrees C, with a substrate-to-catalyst molar ratio (S/C) of 2000 under 50 atm of H-2 in a base-containing 2-propanol to afford the alcohol in 99% ee quantitatively. A series of polysubstituted aromatic ketones was smoothly reacted with an S/C of 300-10,000 under 10-50 atm of H-2, yielding the alcoholic products in up to 99% ee. The catalyst system achieved an industrial-scale (50 kg) hydrogenation of 2',6'-dichloro-3'-fluoroacetophenone, affording the alcohol in 96% isolated yield and in 98% ee. The obtained alcoholic product is known as a key intermediate for the synthesis of the medicine crizotinib.

The asymmetric hydrogenation of aromatic γ- and δ-keto esters into optically active hydroxy esters or diols under the catalysis of a novel DIPSkewphos/3-AMIQ-RuII complex was studied. Under the optimized conditions (8 atm H2 , Ru complex/t-C4 H9 OK=1:3.5, 25 °C) the γ- and δ-hydroxy esters (including γ-lactones) were obtained quantitatively with 97-99 % ee. When the reaction was conducted under somewhat harsh conditions (20 atm H2 , [t-C4 H9 OK]=50 mm, 40 °C), the 1,4- and 1,5-diols were obtained predominantly with 95-99 % ee. The reactivity of the ester group was notably dependent on the length of the carbon spacer between the two carbonyl moieties of the substrate. The reaction of β- and ϵ-keto esters selectively afforded the hydroxy esters regardless of the reaction conditions. This catalyst system was applied to the enantioselective and regioselective (for one of the two ester groups) hydrogenation of a γ-ϵ-diketo diester into a trihydroxy ester.

Double asymmetric hydrogenation of linear β,β-disubstituted α,β-unsaturated ketones catalyzed by the DM-SEGPHOS/DMAPEN/RuII complex with t-C4H9OK afforded the γ-substituted secondary alcohols in high diastereo- and enantioselectivities. Some mechanistic experiments suggested that two different reactive species, type (I) and (II), were reversibly formed in this catalytic system: Type (I) with the diamine ligand DMAPEN enantioselectively hydrogenated the enones into the chiral allylic alcohols, and type (II) without the diamine ligand diastereoselectively hydrogenated the allylic alcohols into the γ-substituted secondary alcohols. This dual catalysis protocol was successfully applied to the reaction of a variety of aliphatic- and aromatic-substituted enone substrates.

Catalytic chemoselective hydrogenation of organic azides using palladium nanoparticles stabilized by alkyne derivatives was studied. A broad range of aromatic and aliphatic azides were smoothly reduced to the corresponding amines in excellent yields with a quite small amount of the catalyst. Hydrogenation of 3-phenylpropylazide gave 3-phenylpropylamine almost quantitatively with a substrate-to-palladium molar ratio (S/Pd) of 12,900 under 8 atm of H-2. The reaction under 1 atm of H2 also proceeded smoothly with an S/Pd of 1000. Several reduction-sensitive functional groups, such as carbonyl, halide, benzylic OH, and aliphatic nitro were well tolerated under the reaction conditions. (C) 2016 Elsevier Ltd. All rights reserved.

Catalytic asymmetric hydrogenation of ketones through the "metal-ligand cooperative mechanism" has been improved in terms of the efficiency, stereoselectivity, and scope of substrates by varying the arrangement of the catalyst structure and reaction conditions. Imino compounds are also smoothly converted to the optically active amines with appropriate catalysts. This type of catalyst exhibits excellent performance on the asymmetric isomerization of primary allylic alcohols into the optically active aldehydes. This personal account describes recent progress on these topics.

Catalytic asymmetric cyanations of prochiral unsaturated compounds affording the corresponding nitrile products in high enantiomeric excess (≥90% in general) are summarized in this review. The nucleophilic cyanide addition onto aldehydes, ketones, and imines is promoted by chiral metal complexes and organocatalysts. Recent progress in asymmetric conjugate cyanation of α,β-unsaturated carbonyl compounds is also discussed. The asymmetric cyanation of unactivated alkenes is catalyzed by chiral transition-metal complexes. Current topics of intramolecular carbocyanation and aminocyanation in addition to the traditional hydrocyanation are reviewed.

Aza-Diels–Alder-type cycloaddition reactions between a range of N-arylimines and functionalized alkenes were effectively catalyzed by the Cr(III)/bipyridine complex under irradiation of blue light, to give the corresponding 1,2,3,4-tetrahydroquinoline derivatives in high yields with excellent diastereoselectivity. Typically, the reaction of benzylideneaniline with 1-vinyl-2-pyrrolidinone proceeded smoothly with a substrate-to-catalyst molar ratio (S/C) of 1000 and completed within 4 h at room temperature (20–25 °C), affording the cycloaddition product in 97% yield.

Irradiation of 3-(hexa-4,5-dienyl)indole derivatives in the presence of 3',4'-dimethoxyacetophenone by a high-pressure mercury lamp through Pyrex glass gave the corresponding [2+2] cycloaddition products stereoselectively in high yields. The major product was a methylenecyclobutane-fused angular tetracyclic spiroindoline derivative produced by the [2+2] cycloaddition through a parallel orientation. The minor product was a hexahydromethanocarbazole derivative through a crossed orientation. Electron-withdrawing substituents, such as acyl or alkoxycarbonyl, on the indole nitrogen were suitable for this reaction. (C) 2019 Elsevier Ltd. All rights reserved.

Palladium nanoparticles stabilized by alkyne derivatives catalyzed the hydrogenation of nitroarenes to the aryl amines in homogeneous phase. The reaction of nitrobenzene proceeded smoothly with a substrate-to-palladium molar ratio (S/Pd) of 51,000 under 8 atm of H2. The reaction under 1 atm of H2 with an S/Pd of 1030 was completed in 4 h. A series of substituted nitroarenes, including 4-acetyl- and 4-formylnitrobenzenes, were converted to the aryl amines with high chemoselectivity.

The ruthenabicyclic complex RuCl((R)- daipena)((R)-dm-segphos) with potassium tert-but- oxide catalyzes the hydrogenation of 2-alkylqui- noxalines and a 3-methyl-2H-1,4-benzoxazine in tol- uene under 20-100 atm of hydrogen at 408 Ct o afford S-configured cyclic amino products in greater than 97% enantiomeric excess {DAIPENA = anion of DAIPEN at the 2-position of an anisyl group, DAIPEN = 1,1-diApropyl-1,2-ethylene- diamine, DM-SEGPHOS = (4,4'-bi-1,3-benzodiox- ole)-5,5'-diylbis(di(3,5-xylyl)phosphine)}. The high catalytic activity results in a turnover number as high as 9400. Hydrogenation of the benzoimine het- erocycles with the RuCl((R)-daipena)((R)-segphos)/ potassium tert-butoxide system yields the R-config- ured products in high enantiomeric excess A=(4,4'-bi-1,3-benzodioxole)-5,5'-diylbis- Ane)). The mode of enantioselec- tion is discussed based on transition state models in- volving six-membered pericyclic structures.

Efficient isomerization: The title reaction was catalyzed by the [RuCl2{(S)-tol-binap}{(R)-dbapen}]/KOH system in ethanol at 25 °C (see scheme). A series of E- and Z-configured aromatic and aliphatic allylic alcohols, including a simple primary alkyl-substituted compound (E)-3-methyl-2-hepten-1-ol, were transformed into the chiral aldehydes with at least 99 % ee. dbapen = 2-dibutylamino-1-phenylethylamine, tol-binap = 2,2'-bis(di-4-tolylphosphanyl)-1,1'-binaphthyl.

Enantioselective hydrogenation of alkynyl ketones catalyzed by Ru(OTf)(TsDPEN)(η(6)-p-cymene) (TsDPEN = N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine) affords the propargylic alcohols in up to 97% ee. The alkynyl moieties are left intact in most cases. The reaction can be conducted with a substrate-to-catalyst molar ratio as high as 5000 under 10 atm of H2. The mode of enantioselection is elucidated with the transition state models directed by the CH/π attractive interaction between the substrate and the catalytic species.

A diastereomerically mixed complex [Ru{(S)-phgly}2{(±)-biphep}] is readily prepared from achiral diphosphine BIPHEP in two steps. These diastereomers are then separated by silica gel column chromat...

A variety of alkoxy-substituted benzolactams with a berbine or yohimbane skeleton were prepared from 1-benzyl-1,2,3,4-tetrahydroisoquinolines or 1-benzyl-1,2,3,4-tetrahydro-β-carbolines by a phosphine-free Pd(II)-catalyzed direct aromatic carbonylation in a Pd(OAc)2-Cu(OAc)2 catalytic system. The site selectivity was compared with that of the carbonylation with Pd(OAc)2 or Pd(OAc)2·2 PPh3, respectively.

Catalytic asymmetric cyanations of prochiral unsaturated compounds affording the corresponding nitrile products in high enantiomeric excess (≥90% in general) are summarized in this review. The nucleophilic cyanide addition onto aldehydes, ketones, and imines is promoted by chiral metal complexes and organocatalysts. Recent progress in asymmetric conjugate cyanation of α,β-unsaturated carbonyl compounds is also discussed. The asymmetric cyanation of unactivated alkenes is catalyzed by chiral transition-metal complexes. Current topics of intramolecular carbocyanation and aminocyanation in addition to the traditional hydrocyanation are reviewed.