Asymmetric Entry Research Articles

Benzylic-type couplings provide an important asymmetric entry to functionalized, non-racemic helicenes

Benzylic-type couplings are key reactions to make non-racemic helicenes.

Intramolecular Vinyl Quinone Diels–Alder Reactions: Asymmetric Entry to the Cordiachrome Core and Synthesis of (−)-Isoglaziovianol

A short and asymmetric entry to the core structure of the cordiachromes has been developed, allowing access to (-)-isoglaziovianol in seven steps. Our synthesis includes a Trost asymmetric allylic alkylation and a reaction cascade triggered by a vinyl quinone Diels-Alder reaction and followed by intramolecular nucleophilic interception.

Location strategies of multinational banking under risk and asymmetric information

PurposeInspired by the recent opening up of the Chinese banking market and by the ensuing location strategies adopted by foreign banks, the purpose of this paper is to develop an empirical analysis on location strategies. The paper enriches the existing literature by including many important realistic aspects, some of which have never been analyzed in theory before, especially for firms entering an unfamiliar and risky foreign market.Design/methodology/approachThe authors carried out an empirical study on foreign banks' entry to the newly opened up Chinese banking market and modelled location strategies of foreign banks in China as a conditional logit problem, in which the dependent variable is the market chosen by an investor. To investigate the determinants of foreign banks' location choices in China, the authors collected data of foreign banks' entries into China during 1980‐2006.FindingsThe main empirical results are: asymmetric information, firm size and entry sequence are significant determinants of foreign banks' location strategies.Originality/valueThe paper presents a new set of results.

Environmentally Sustainable National Income: Indispensable Information for Attaining Environmental Sustainability

Environmental functions are defined as the possible uses of the non-human-made physical surroundings on which humanity is entirely dependent. Competing functions are by definition economic goods, indeed the most fundamental humanity disposes of. Environmental sustainability is defined as the dynamic equilibrium by which vital environmental functions remain available for future generations. Environmentally sustainable national income (eSNI) is defined as the maximum attainable production level by which vital environmental functions remain available for future generations. Thus the eSNI provides information about the distance between the current and a sustainable situation. In combination with the standard national income (NI), the eSNI indicates whether the part of the production that is not based on sustainable use of the environment is increasing or decreasing in the course of time. Calculation of the eSNI involves the use of environmental models and a static general economic equilibrium model. It is shown that asymmetric entries are obscuring what is happening with both environment and production and that there is no conflict between employment and safeguarding the environment.

Some Comparative Statics Of Entry In Markets With Demand Complementarities

This paper develops a two-market Cournot model with complementary demands to investigate comparative statics associated with symmetric and asymmetric entry. Notably, while market prices are decreasing with the number of market rivals, asymmetric entry actually causes prices to rise in the adjacent, complementary market. In addition, the price-decreasing effects of symmetric entry are attenuated with strong cross-price effects.

ChemInform Abstract: One‐Step Catalytic Enantioselective α‐Quaternary 5‐Hydroxyproline Synthesis: An Asymmetric Entry to Highly Functionalized α‐Quaternary Proline Derivatives.

The highly enantioselective cascade reaction between N-protected a-cyanoglycine esters and a,beta-unsaturated aldehydes is disclosed. The reaction represents a one-step entry to polysubstituted 5-h ...

One‐Step Catalytic Enantioselective α‐Quaternary 5‐Hydroxyproline Synthesis: An Asymmetric Entry to Highly Functionalized α‐Quaternary Proline Derivatives

AbstractThe highly enantioselective cascade reaction between N‐protected α‐cyanoglycine esters and α,β‐unsaturated aldehydes is disclosed. The reaction represents a one‐step entry to polysubstituted 5‐hydroxyproline derivatives having a quaternary α‐stereocenter generally in high yields with up to >95:5 dr and 99:1 er. It is also a direct catalytic two‐step entry to functionalized α‐quaternary proline derivatives.

Sustainable national income: information for attaining sustainability

PurposeThis paper aims to provide information about which conditions green supply chains have to fulfil in order to attain an environmentally sustainable situation.Design/methodology/approachThe paper describes a macro economic analysis in which, first, the non‐human – made physical surroundings is described as a collection of possible uses, or environmental functions, on which human life is entirely dependent. Second, the possibilities and impossibilities of evaluating environmental functions are described. Third, it is stated that competing functions are by definition economic goods. Fourth, the concepts of national income (NI) ex asymmetric entries and the environmentally sustainable national income (eSNI) are formulated. Fifth it is shown why the estimate of eSNI has to be realised with the aid of an economic model. Sixth, it is argued why there is no conflict between environmental conservation and employment. Finally, the relation of this analysis and supply chains is given.FindingsThe results of an environmentally sustainable production level (the eSNI) is given, both for The Netherlands and for the world. It is found that a series NIs ex asymmetric entries and a series of eSNIs alongside the standard NI would greatly ameliorate the information about the inevitable choices between the growth of production and safeguarding vital environmental functions for future generations.Originality/valueBoth the concepts presented and the results of the estimates are original.

CFD modeling of 2D asymmetric entry impact along with horizontal velocity

The 2D impact phenomenon in calm water, considering asymmetric entry and asymmetric entry withhorizontal velocity is studied. The analysis was performed by using a commercial CFD software (STARCCM+©). The results obtained from the simulations are: pressure distribution, force and roll moment.The study was carried out for typical planing boat sections. Furthermore, the critical conditions requiredfor flow separation from the keel are also determined. The results are compared with models and resultsobtained from some authors and they present very good agreement.

ChemInform Abstract: Regio- and Stereocontrolled Metal-Mediated Carbonyl Propargylation or Allenylation of Enantiomerically Pure Azetidine-2,3-diones: Synthesis of Highly Functionalized 3-Substituted 3-Hydroxy-β-lactams.

Regio- and stereocontrolled metal-mediated Barbier-type reactions of azetidine-2,3-diones with differently substituted propargyl bromides offer an efficient asymmetric entry to densely functionalized 3-propargyl- (or allenyl-) substituted 3-hydroxy-β-lactams.

A view from the top: new ligands controlling stomatal development in Arabidopsis

A view from the top: new ligands controlling stomatal development in Arabidopsis

Organocatalytic Michael Addition of Aldehydes to Vinyl Sulfones: Enantioselective α-Alkylations of Aldehydes and Their Derivatives

Organocatalytic asymmetric Michael reaction of unmodified aldehydes to vinyl sulfones catalyzed by silylated biarylprolinol afforded the desired Michael products with exceptional enantioselectivity. The described enantioselective addition to vinyl sulfones, in combination with desulfonation, offers a unique, asymmetric entry to alpha-alkylated aldehydes and their derivatives.

ChemInform Abstract: Catalytic Enantioselective 5‐Hydroxyisoxazolidine Synthesis: An Asymmetric Entry to β‐Amino Acids.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Direct, Catalytic Enantioselective Nitroaldol (Henry) Reaction of Trifluoromethyl Ketones: An Asymmetric Entry to α‐Trifluoromethyl‐Substituted Quaternary Carbons.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Auction design with opportunity cost

This paper studies revenue-maximizing auctions in an independent private value setting where potential bidders have known positive opportunity cost of bidding. The main findings are as follows. Firstly, there is no loss of generality in deriving the revenue-maximizing auctions within the class of threshold-entry mechanisms. Secondly, for any given set of entry thresholds, a second-price sealed-bid auction with properly set reserve prices and entry subsidy is revenue-maximizing. Thirdly, a variety of auctions are revenue-maximizing within the symmetric threshold-entry class. Two of them involve no entry subsidy (fee). Fourthly, we identify sufficient conditions under which it is in the seller’s interest to limit the number of potential bidders even if the revenue-maximizing symmetric threshold-entry auction is adopted. Lastly, the revenue-maximizing auction implements asymmetric entry across symmetric bidders in many cases.

Catalytic Enantioselective 5-Hydroxyisoxazolidine Synthesis: An Asymmetric Entry to β-Amino Acids

The highly chemo- and enantioselective organocatalytic tandem reaction between N-carbamate-protected hydroxylamines and a,p-unsaturated aldehydes is presented. The reaction represents a unique entry for the asymmetric synthesis of 5-hydroxyisoxazolidines, oxazolidin-5-ones or gamma-hydroxyamino alcohols in high yields and 90-99% ee. A procedure for the conversion of the oxazolidin-5-ones into the corresponding beta-amino acids is also described.

Direct, Catalytic Enantioselective Nitroaldol (Henry) Reaction of Trifluoromethyl Ketones: An Asymmetric Entry to α-Trifluoromethyl-Substituted Quaternary Carbons

Herein we describe the first direct, catalytic enantioselective nitroaldol (Henry) reaction of simple alpha-trifluoromethyl ketones with nitromethane using a chiral monometallic lanthanum(III) triflate salt complex, namely [(Delta,S,S,S)-Binolam]3.La(OTf)3, as enantioselective catalyst. The resulting alpha-trifluoromethyl tertiary nitroaldols were obtained in moderate to high yields (up to 93%) and enantioselectivities (up to 98% ee). These adducts are versatile chiral building blocks and may be reduced (NiCl2/NaBH4) to their beta-amino-alpha-trifluoromethyl tertiary alcohols without loss of enantiomeric purity.

A Simple and Concise Catalytic Asymmetric Entry to Tetrahydroxanthenones.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

A One‐Pot Organocatalytic Asymmetric Entry to Tetrahydrothioxanthenones.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

A simple and concise catalytic asymmetric entry to tetrahydroxanthenones

The first catalytic asymmetric synthesis of tetrahydroxanthenones is presented. The simple organocatalytic enantioselective domino reactions between salicylic aldehyde derivatives and α,β-unsaturated cyclic ketones proceed with excellent chemoselectivity to give the corresponding tetrahydroxanthenones in moderate to good yields and high enantioselectivities.