Learning to align organizational design and data

The relationship between organizational learning and organizational design is explored. In particular, we examine the information processing aspects of organizational learning as they apply to a two-valued decision making task and the relation of such aspects to organizational structure. Our primary contribution is to extend Carley's (1992) model of this process. The original model assumes that all data input into the decision making processes are of equal importance or weight in determining the correct overall organizational decision. The extension described here allows for the more natural situation of non-uniform weights of evidence. Further extensions to the model are also discussed. Such organizational learning performance measures provide an interesting framework for analyzing the recent trend towards flatter organizational structures. This research suggests that flatter structures are not always better, but rather that data environment, ultimate performance goals, and relative need for speed in learning can be used to form a contingency model for choosing organizational structure.     

Catalytic, asymmetric synthesis of α,α-disubstituted amino acids

Copper(salen) complex 1 has been found to catalyse the asymmetric alkylation of enolates derived from a variety of amino acids. There is a clear relationship between the size of the side chain in the substrate and the enantioselectivity of the process, so that the enantioselectivity decreases in the order alanine>aminobutyric acid>allylglycine>leucine>phenylalanine>valine. A transition state model which accounts for the influence of the size of the side chain on the enantioselectivity of the reactions is presented.     

Fluorinated polysilanes. Palladium catalyzed 1,4-addition of fluorodisilanes to conjugated diene and enone systems

In the presence of palladium complexes as catalysts, fluorinated disilanes add to 1,3-dienes, metehyl vinyl ketone and p-benzoquinone to give mainly 1,4-addition products.     

N-(6-甲基-2-亚甲基吡啶)-( )-樟脑亚胺体系的不对称烷基化反应

目前,不对称合成光学活性化合物取得了较大进展,不对称合成α-氨基酸、β-氨基醇、α-取代苄胺的报道很多。但是,不对称合成生物碱类物质——α-取代氨甲基吡啶类化合物还未见文献报道,而此类化合物有潜在的应用前景。为此,我们以( )-樟脑为手性试剂     

Useful dual Diels-Alder behavior of 2-azetidinone-tethered aryl imines as azadienophiles or azadienes: a beta-lactam-based stereocontrolled access to optically pure highly functionalized indolizidine systems

Imines derived from 4-oxoazetidine-2-carbaldehydes have been found to be versatile Diels-Alder reagents in that they exhibit two reactivity patterns. 2-Azetidinone-tethered imines undergo diastereoselective reaction with Danishefsky's diene in the presence of different Lewis acids. The effect of the amount of catalyst on the conversion rate as well as on the product ratio has been studied. Under standard reaction conditions, indium(III) chloride and zinc(II) iodide provided the best yields, and indium(III) triflate the highest diastereoselectivity in the Lewis acid promoted aza-Diels-Alder cycloaddition. Treatment of the aforementioned imines with cyclopentadiene, 2,3-dimethyl-1,3-butadiene or 3,4-dihydro-2 H-pyran led to cycloadducts arising from inverse electron-demand condensation involving the beta-lactam-tethered aryl imine as the heterodiene component. In addition, the first methodology for preparing indolizidines from beta-lactams has been developed. This process involves amide bond cleavage of the beta-lactam ring in the aza-Diels-Alder cycloadducts with concomitant cyclization. Full chirality transfer occurs when the reaction is performed with an enantiomerically pure substrate.     

Asymmetric Diels–Alder reactions in supercritical carbon dioxide catalyzed by rare earth complexes

The rare earth(III) salt catalysed asymmetric Diels–Alder reaction of cyclopentadiene with a chiral dienophile in supercritical carbon dioxide (scCO₂) proceeded rapidly to give the adduct with a higher diastereoselectivity than that in dichloromethane; Yb(ClO₄)₃ gave the endo adduct with value up to 77% de at 40°C, 8 MPa. The chiral rare earth diketonate catalyzed hetero Diels–Alder reaction of the Danishefsky's diene with benzaldehyde gave a higher yield and an enantioselectivity in scCO₂ than that in dichloromethane. Scandium/pybox 8a complex catalysed asymmetric Diels–Alder reaction of 3-crotonoyl-2-oxazolidinone with cyclopentadiene in the presence of MS4A proceeded smoothly in scCO₂ to give the endo adduct 10 in a good yield with up to 88% ee.     

Synthesis and applications of photochromic fulgides in optical information storages

A pyrryl substituted photocbromic fulgide, (1-p-methoxyphenyl-2-methyl-5-phenyl)-3-pyrryl-ethylidene (isopropylidene) succinic anhydride, was synthesized. Its chemical structure was identified by IR, 1H NMR MS and elemental analysis. The title compound was used to prepare the optical disks by the spin coating method and the vacuum evaporation method. The results of the static state examination show that the optical disks prepared with this kind of molecules possess excellent thermal stability and fatigue resistance, i.e. over 450 writing-erasing recycles, the relative contrast between writing state and erasing state remains at 40%.     

An aldol approach to the total synthesis of (+)-brefeldin A

A convergent selective route to (+)-brefeldin A (BFA) and 7-epi-BFA was developed, with the crucial C-4/C-5 stereogenic centers were established using Crimmins asymmetric aldolization.