다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

A stepwise huisgen cycloaddition process: copper(I)-catalyzed regioselective "ligation" of azides and terminal alkynes.

3.2.3. Hydroformylation 2467 3.2.4. Dimerization 2468 3.2.5. Oxidative Cleavage and Ozonolysis 2469 3.2.6. Metathesis 2470 4. Terpenes 2472 4.1. Pinene 2472 4.1.1. Isomerization: R-Pinene 2472 4.1.2. Epoxidation of R-Pinene 2475 4.1.3. Isomerization of R-Pinene Oxide 2477 4.1.4. Hydration of R-Pinene: R-Terpineol 2478 4.1.5. Dehydroisomerization 2479 4.2. Limonene 2480 4.2.1. Isomerization 2480 4.2.2. Epoxidation: Limonene Oxide 2480 4.2.3. Isomerization of Limonene Oxide 2481 4.2.4. Dehydroisomerization of Limonene and Terpenes To Produce Cymene 2481

Chemical Routes for the Transformation of Biomass into Chemicals

A. Water Exchange 2326 B. Proton Exchange 2327 C. Electronic Relaxation 2327 D. Relaxivity 2331 E. Outerand Second-Sphere Relaxivity 2334 F. Methods of Improving Relaxivity 2336 V. Macromolecular Conjugates 2336 A. Introduction 2336 B. General Conjugation Methods 2336 C. Synthetic Linear Polymers 2336 D. Synthetic Dendrimer-Based Agents 2338 E. Naturally Occurring Polymers (Proteins, Polysaccharides, and Nucleic Acids) 2339

https://mriquestions.com/uploads/3/4/5/7/34572113/lauffer_1999_review.pdf

Gadolinium(III) Chelates as MRI Contrast Agents: Structure, Dynamics, and Applications

Encoding and decoding hydrogen-bond patterns of organic compounds

Self-Assembling Capsules

Binding of guests in self-assembled or covalently linked capsules is shown to be related to the occupancy factor or packing coefficient. Optimal binding can be expected when this value (defined as the ratio between the guest volume and the host cavity volume; right) is in the range 0.55±0.09. This is also shown to reflect the space filled in typical organic solvents. An analysis of different guests and hosts capable of reversible binding suggests a rule of general applicability as to what constitutes a good fit.

The 55 % Solution: A Formula for Molecular Recognition in the Liquid State

THE interior of cage-like molecules can be considered to provide a new phase of matter1,2, in which it becomes possible to stabilize reactive intermediates3 and to observe new forms of stereoisomerism4. Cage-like molecular complexes that self-assemble through weak intermolecular forces are dynamic species5,6, encapsulating guest molecules reversibly. They can persist over timescales ranging from microseconds to hours, long enough for chemical processes to take place within them. Here we report the acceleration of a Diels–Alder reaction by encapsulation of the reac-tants in a self-assembling molecular capsule7,8. Although product inhibition (lack of dissociation) prevents the system from showing true catalytic behaviour, there is clear evidence for a rate increase of over two orders of magnitude owing to the effective enhancement of concentration inside the capsule.

Acceleration of a Diels–Alder reaction by a self-assembled molecular capsule

Reversible encapsulation creates spaces where molecules are temporarily isolated from others in solution. Molecules are held within the space of the capsule for lifetimes ranging from milliseconds to hours, and conventional NMR spectroscopy can be used to report on the chemical and magnetic environment as well as the arrangement of the molecules in the encapsulation complex. The complexes self-assemble when, and only when, the spaces inside the capsules are appropriately filled. The weak intermolecular forces that hold these self-assemblies together allow equilibration of the encapsulation complexes at ambient temperatures and pressures in the liquid phase. When two or more molecules are simultaneously encapsulated, intermolecular phenomena are revealed in solution that cannot be observed by other methods. We describe here the unique behavior that emerges from molecules that are simultaneously encapsulated and includes new forms of stereochemistry, isomerism, and asymmetry inside capsules.

Simultaneous encapsulation: Molecules held at close range

How structures fit together is the principal domain of molecular recognition, and current studies are evolving from the host–guest chemistry of ions to interactions between two molecules. Recent advances in the synthesis of sizable concave molecules, especially those featuring convergent functional groups, make it possible to bind smaller convex structures with considerable selectivity. One result is that hydrogen bonding can be addressed in model systems. The present review emphasizes the use of cleftlike structures as a means of probing the forces involved in nucleic acid recognition. The application of such molecules to the catalysis of chemical reactions, particularly those involved in self-replicating systems, is also described. Some implications for future pharmaceutical agents are suggested as a result of access to synthetic receptors for biologically relevant targets.

Julius Rebek

Papers

Self-Assembling Capsules

The 55 % Solution: A Formula for Molecular Recognition in the Liquid State

Acceleration of a Diels–Alder reaction by a self-assembled molecular capsule

Simultaneous encapsulation: Molecules held at close range

Molecular Recognition with Model Systems