Takahiko Inazu

A facile synthesis of [3ncyclophanes, in which aromatic rings are connected with -CH2CO-CH2- bridges☆

Abstract The title compounds, I, were synthesized by the dialkylation of TosMIC, II, with appropriate bis (halomethyl) compounds, III, under phase-transfer condition, followed by acid hydrolysis.

Nitrogen-bridged macrocycles: synthesis, structures and inclusion phenomena

Abstract Synthetic methods of nitrogen-bridged macrocyche best molecules such as highly symmetrical cage compounds 3 6 and their bond isomers 8, 10 , azacalix [ n ]atenes 16, 18 and 20 and tetraaza[3 4 ]cyclophanes 24 and 31 , are summarized. The new class of macrocycles 3–6 were designed and synthesized by one-step coupling reactions. In the compounds, pyridine or benzene units are connected by four bridgehead nitrogens, and both pyridine and bridgehead nitrogen lone pairs are directed into the cavity. The bridgehead nitrogen inversion is inhibited by the rigid structure. Because of tthe preorganized structure of 5 and 6 with four and six pyridine donors, respectively, they strongly bind alkali metal and ammonium ions, as exemplified by the fact that they are obtained as the K + complexes in the coupling reactions. The compound 5 showed Rb + selectivity among alkali metal ions, and the structure of its K + complex was confirmed by X-ray structural analysis. The hosts 5 and 6 also form very stable proton cryptates (H + ∋ 5 ·OH − or H + ∋ 6 ·OH − ). They are relatively stable, but very slowly changed into water cryptates (H 2 O∋ 5 or H 2 Oχ 6 ). The cation affinity of the host can be controlled by attaching electron-donating or -withdrawing substituents on the pyridine rings. A Cl − ion formed the complex with 6 in acidic solution, but Br − , I − and other anions larger than Cl − could not be encapsulated by 6 . The azacalixarenes, a new family of calix[ n ]arenes, have more rigid structure than the corresponding oxacalix[ n ]arenes and calix[ n ]arenes because of the strong intramolecular hydrogen bonds between phenolic hydroxyl groups and nitrogen lone pairs.

An extremely efficient synthesis of thiophene 1,1-dioxides. Oxidation of thiophene derivatives with dimethyldioxirane

Abstract Dimethyldioxirane was found to oxidize electron-rich thiophene derivatives, including sterically hindered thiophenophanes, to the corresponding thiophene 1,1-dioxides in excellent yields. Electronwithdrawing groups on a thiophene ring substantially retarded the oxidation, but dimethyldioxitane remained superior to other reagents.

The first synthesis and properties of hexahomotriazacalix[3]arene

Abstract The reaction between 2,6-bis(hydroxylmethyl)-4-methylphenol and benzylamine afforded N,N′,N″-tribenzyl-6,15,24-trimethyl-9,18, 27-trihydroxy-2,11,20-triaza[3.3.3]metacyclophanes.

A novel hindered macrocyclic tetramine containing two bispidine units. A new type of proton sponge

Abstract A novel cyclam-like macrocyclic tetramine 1a was synthesized via coupling of bispidine and its bis(α-chloroacetamide) followed by reduction. Strongly basic but encrypted nitrogens of 1a were found to abstract a proton from chloroform to form dichlorocarbene.

Conformational analysis of 12,12,21,21-tetradeuterio-1,4-dioxa-[4.3.3](1,3,5)Cyclophane☆

Abstract All possible three conformers (chair-chair, chair-boat, and boat-boat) of the title compound were detected by 1H NMR spectrum below 223K(−50°C).

NOVEL C2 CHIRAL DIAMINE LIGANDS DERIVED FROM CYCLIC TROGER BASES

Abstract The endomethylene bridge in a macrocyclic Troger base was removed efficiently to provide a dibenzodiazocine derivative, and its N-methyl and N,N′-dimethyl derivatives. These C2 chiral diamines could be separated into their optical antipodes by HPLC using a chiral column. Complex formation of these new type ligands with several metal salts was also examined.

The Proton Cryptate of Hexaethylenetetramine

The next higher homologue of hexamethylenetetramine was synthesized as the proton cryptate H+ @1⋅Br- (shown schematically), and its X-ray structure determined. The proton trapped by the lone pairs accumulated at the center of the T-symmetric tetraaza cage could not be exchanged or removed, even after heating for three days in 3 M NaOD.

A POTASSIUM COMPLEX OF A FLUORINE-CONTAINING MACROCYCLIC CAGE COMPOUND : INTERACTIONS BETWEEN FLUORINE ATOMS AND METAL IONS

A new donor, the C-F unit, can be added to the field of host-guest chemistry. The interaction between fluorine atoms and a potassium ion was proven with the fluorine-containing cage compound 1 as a host. The six fluorine atoms of K+ ⊂1 are coordinated to K+ in a distorted octahedral fashion.

Synthesis of [1.1.1.1]paracylophane

Abstract The title compound 1 has been synthesized by a route involving acyloin cyclization, pyrolytic elimination of a diacetate 5 derived from the acyloin 4 , and the Diels-Alder reaction of the resultant 1,3-diene 6A with phenyl vinyl sulfoxide.