摘要：
A novel three-component, one-pot condensation yielding 2-amino-4H-1,3-oxazines or 2-amino-4H-1,3-thiazines from alkynes, urea or thiourea, and aldehydes is described. [reaction: see text]
作者机构：
[Li, YT; Wu, AX; Yin, GD; Zhou, BH] Cent China Normal Univ, Coll Chem, Minist Educ, Key Lab Pesticides & Chem Biol, Wuhan 430079, Peoples R China.
通讯机构：
[Wu, AX] C;Cent China Normal Univ, Coll Chem, Minist Educ, Key Lab Pesticides & Chem Biol, Wuhan 430079, Peoples R China.
摘要：
In the title compound, C26H40N6O6, the five-membered rings adopt envelope conformations and the six-membered rings are in chair conformations. The crystal packing is stabilized by C—H⋯O hydrogen bonds.
期刊：
JOURNAL OF ORGANIC CHEMISTRY,2004年69(19):6157-6164 ISSN：0022-3263
通讯作者：
Isaacs, L
作者机构：
[Isaacs, L] Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA.;Cent China Normal Univ, Coll Chem, Hubei 430079, Peoples R China.
通讯机构：
[Isaacs, L] U;Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA.
摘要：
Self-sorting-the ability to efficiently distinguish between self and nonself-is common in nature but is still relatively rare in synthetic supramolecular systems. We report a 12-component mixture comprising 1-11 and KCl that undergoes thermodynamically controlled self-sorting in aqueous solution based on metal-ligand, ion-dipole, electrostatic, charge-transfer interactions, as well as the hydrophobic effect. We refer to this molecular ensemble-characterized by high-fidelity host-guest interactions between components-as a social self-sorting system to distinguish it from narcissistic self-sorting systems based on self-association processes. The influence of several key variables-temperature, pH, concentration, and host/guest stoichiometry-was explored by a combination of simulation and experiment. Variable temperature NMR experiments, for example, revealed a kinetically controlled irreversible process upon cycling from 298 to 338 K, which is an emergent property of this molecular ensemble. Variable pH and concentration experiments, in contrast, did not reveal any emergent properties of the molecular ensemble. Simulations of a four-component mixture establish that by proper control of the relative magnitude of the various equilibrium constants, it is possible to prepare socially self-sorted mixtures that are responsive (irresponsive) to host/guest stoichiometry over narrow (broad) ranges. The 12-component mixture is relatively irresponsive to host/guest stoichiometry. Such social self-sorting systems, like their natural counterparts, have potential applications as chemical sensors, as artificial regulatory elements, and in the preparation of biomimetic systems.
