Corey studies

Corey studied the X-ray crystal structures of cinchonidinium salts and has formulated a model which explains the highly enantioselective alkylation of the enolate of 3 [3]. This model accounts for the sense of asymmetric induction in this process and the importance of the size of the R1 substituent in the salts 1 and 2 the model can be used to rationalise other phase transfer catalysed processes involving similar catalysts. The enolate 37 is thought to be in close contact with the least hindered face of the tetrahedron formed by the four atoms surrounding the quaternary nitrogen atom (the rear face of this tetrahedron is blocked by the bulky 9-anthracenylmethyl group). Alkylation of the less hindered face of 37 leads to the observed enantiomer of the product (see Figure 1). 

The first rationalization of the tendency of aglycons of alkyl glycopyranosides to assume axial orientation was proposed by Edward [12] and most probably was inspired by the Corey study on the stereochemistry of some a-halocyclohexanones [13], in which it was determined that the most stable conformation of a-chloro-and a-bromocyclohexanone is the chair form, in which the halogen substituent is axial (2 in Fig. 2.1). 

The primary structure of a peptide is its ammo acid sequence We also speak of the secondary structure of a peptide that is the conformational relationship of nearest neighbor ammo acids with respect to each other On the basis of X ray crystallographic studies and careful examination of molecular models Linus Pauling and Robert B Corey of the California Institute of Technology showed that certain peptide conformations were more stable than others Two arrangements the a helix and the (5 sheet, stand out as... 

This work has been carried out in association with Professor Elias J. Corey, who suggested the study of protective groups for use in computer-assisted synthetic analysis. 1 appreciate his continued help and encouragement. I am grateful to Dr. 

Another chiral titanium reagent, 11, was developed by Corey et al. [17] (Scheme 1.24). The catalyst was prepared from chiral ris-N-sulfonyl-2-amino-l-indanol and titanium tetraisopropoxide with removal of 2-propanol, followed by treatment with one equivalent of SiCl4, to give the catalytically-active yellow solid. This catalyst is thought not to be a simple monomer, but rather an aggregated species, as suggested by NMR study. Catalyst 11 promotes the Diels-Alder reaction of a-bro-moacrolein with cyclopentadiene or isoprene. 

Corey et al. reported that the catalyst 19, prepared from trimethylaluminum and the bis-trifluorosulfonamide of stilbenediamine (stien), with generation of methane, is a suitable catalyst for the Diels-Alder reaction of 3-acryloyl, and 3-crotonoyl-l,3-oxazo-lidin-2-ones, giving the cycloadducts in high optical purity [28] (Scheme 1.35, Table 1.14). X-ray structure analysis of the catalyst and and NMR studies revealed that... 

As the phosphonium diylides, lithium phosphonium yldiides, first described by Schlosser and Corey (Ph3P=CR-Li R=H, C3H7) [60-62], have a high nucleophilicity and reactivity. Recently, the a-silylated lithium phosphonium yldiide 20 has been prepared from the stable phosphanyl-(silyl)carbene 19 and alkyl-lithium (Scheme 13). The first crystal X-ray diffraction study of such a reagent was proposed for 20 and its reaction with methyl iodide or phosphorus elec-... 

Concerning the yldiide Ph3P=CH-Li, the question as to whether it could be obtained by direct lithiation of the ylides 23 (Y=H), for a long time in debate between Schlosser and Corey, could have found an answer. Effectively NMR studies seem to show that a directed ortho-metallation occurs on an aromatic ring when 23 is reacted with t-BuLi [65], leading thus to the formation of 24 whose evolution does not afford Ph3P=CH-Li (Scheme 13). 

Corey et al. [19] simultaneously reported similar studies using a2,2 -bis(oxazolyl)-6,6 -dimethyl-l,l -biphenyl as copper(I)triflate chelate. This hgand afforded a stable monomeric chiral Cu(I) complex providing a highly... 

Lazarou J, Pomeranz BH, Corey PN. Incidence of adverse drug reactions in hospitalized patients a meta-analysis of prospective studies. JAMA. 1998 Apr 15 279(15) 1200-5. 

Corey-Bloom J, Anand R, Veach J, for the ENA 713 B352 Study Group (1998). A randomised trial evaluating the efficacy and safety of ENA 713 (rivastigmine tartrate), a new acetylcholinesterase inhibitor, in patients with mild and moderately severe Alzheimer s disease. IntJGeriatrPsychopharmacolX, 55-65. 

Many catalytic reactions involve the activation of Si—H bonds and consequently the reaction of silanes with platinum(0) has been studied extensively. The reactions of hydrosilanes with transition-metal complexes, including platinum, has been extensively reviewed by Corey and Braddock-Wilking.58... 

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