Silica‐supported ICl as a novel heterogeneous system for the rapid oxidation of urazoles to triazolinediones

ICl–SiO₂ as a new reactive system was prepared by the treatment of iodine monochloride with an activated silica gel in chloroform. ICl–SiO₂ in a heterogeneous system efficiently oxidized urazoles to the corresponding triazolinediones under mild conditions in high yields at room temperature. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:389–393, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20444     

A facile and convenient synthesis of tetrasubstituted N‐hydroxypyrroles via intramolecular wittig reaction

Treatment of triphenylphosphine with dialkyl acetylenedicarboxylate leads to 1:1 adduct and concomitant protonation of late adduct by pentan‐2,3,4‐trione 3‐oxime gave the reactive intermediate, vinyltriphenylphosphonium salts, which undergoes an intramolecular Wittig reaction to produce tetrasubstituted N‐hydroxypyrroles in fairly high yields. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:100–103, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20382     

Cobalt(II) chloride as a novel and efficient catalyst for the synthesis of 1,2,5‐trisubstituted pyrroles under solvent‐free conditions

CoCl₂ is used as an efficient catalyst in the Paal–Knorr condensation of 2,5‐hexadione with primary amines under solvent‐free conditions, leading to the formation of pyrrole derivatives in excellent yield. This method is very easy, rapid, and high yielding reaction for the synthesis N‐substituted pyrrole derivatives. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:592–595, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20482     

Diastereoselective addition of hypophosphorous acid to N‐(R)‐α‐methylbenzyl‐substituted schiff bases

The addition of hypophosphorous acid to an azomethine bond of N‐(R)‐α‐methylbenzyl Schiff bases of a variety of aldehydes led to the formation of N‐(R)‐α‐methylbenzylamino‐(S)‐methanephosphonous acids in 100% diastereoselectivity. This fact allows us to suggest the probable mechanism of the Strecker‐like reaction between hypophosphorous acid, an aldehyde, and (R)‐α‐methylbenzylamine. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:35–37, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20406     

LiClO4 catalyzed mild and efficient method for the synthesis of thiiranes from oxiranes

Oxiranes are efficiently converted to the corresponding thiiranes by potassium thiocyanate in the presence of catalytic amounts of LiClO₄ with excellent yields under mild and nonaqueous conditions. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:97–99, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20376     

A convenient and practical method for the synthesis of N‐thiophosphoryl aldimines and ketimines

A convenient and practical method for the preparation of N‐thiophosphoryl imines was developed through the thermal condensation of acetals with different thiophosphoramides at 120–160°C. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:238–244, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20412     

MnCl2‐Promoted synthesis of quinoxaline derivatives at room temperature

MnCl₂ efficiently catalyzes the condensation of o‐phenylenediamine derivatives with 1,2‐diketones at room temperature to afford the corresponding quinoxaline derivatives in high yields. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:218–220, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20401     

Diversity‐oriented synthesis

Diversity‐oriented synthesis (DOS), which describes the synthesis of structurally diverse collections of small molecules, was developed, in part, to address combinatorial chemistry's shortfalls. In this paper, we hope to give an indication of what can be achieved using the DOS approach to library generation. We describe some of the most successful strategies utilized in DOS, with special focus on our own area of interest; DOS from simple, pluripotent starting materials. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 129–142; 2008: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.20144     

A group of 3D graphical representation of DNA sequences based on dual nucleotides

Based on chemical properties of the neighboring dual nucleotides, we reduce a DNA sequence into four 3D graphical representations. Associating with the eigenvalues of the introduced covariance matrix and the introduced measure of similarity, we introduce an approach to make similarity analysis of DNA sequence. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008     

Facile synthesis of selenocarboxamides from nitriles using Se/CO/H2O under atmospheric pressure

Aromatic and aliphatic nitriles can be conveniently converted into the corresponding selenocarboxamides with Se/CO/H₂O under atmospheric pressure without use of a base. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:211–214, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20398     

A simple and efficient preparation of pyrazolo[3,4‐b]‐pyridine derivatives through an unexpected reaction of cyanothioacetamide under microwave irradiation

An unexpected multicomponent reaction of cyanothioacetamide with aromatic aldehydes and aminopyrazole under MWI was found and reported. It turned out to be an efficient and simple procedure for the preparation of pyrazolo[3,4‐b]pyridine derivatives. The structure of the product was characterized by IR, MS, ¹H and ¹³C NMR, COSY and NOESY spectroscopy, X‐ray crystallographic analysis, and by comparison with the authentic sample prepared with the known procedure. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:694–699, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20497     

Efficient synthesis of 5H‐thiazolo[3,2‐a]pyrimidines from reactions of 3,4‐dihydropyrimidine‐thiones with α‐bromoacetone in aqueous media

An efficient and convenient method for thiazolo[3,2‐a]pyrimidines from cyclization reaction of dihydropyrimidine‐thiones with α‐bromoacetone in aqueous media is described. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:149–153, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20386     

Kaolin: A recyclable catalyst for the synthesis of 1,5‐benzodiazepines

2,3‐Dihydro‐1H‐1,5‐benzodiazepines are synthesized by the condensation of o‐phenylenediamine and various ketones in the presence of kaolin as a recyclable catalyst in dichloroethane. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:215–217, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20354     

Synthesis of novel chiral Schiff bases and their application in asymmetric transfer hydrogenation of prochiral ketones

Novel chiral Schiff bases were synthesized from (+)‐camphor, and their application to asymmetric transfer hydrogenation of prochiral ketones is described. The asymmetric transfer hydrogenation reaction could afford excellent conversion rates (up to 97.3%) and up to 27.3% enantiomeric excess. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:682–687, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20494     

N → C2 → C3 migration of the dichlorophosphino group in the synthesis of phosphorylated NH‐pyrroles

A successive N → C₂ → C₃ migration of the dichlorophosphino group has been found to occur in phosphorylation of unsubstituted pyrrole with phosphorus trichloride. As a result of this migration, a number of hitherto unknown C‐phosphorylated N‐unsubstituted pyrroles have been obtained. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:671–676, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20495     

Bismuth triflate catalyzed prins‐type cyclization in ionic liquid: Synthesis of 4‐tetrahydropyranol derivatives

The reaction of aldehydes with homoallylic alcohols in the presence of catalytic amount of bismuth triflate in [bmim]PF₆generates 4‐tetrahydropyranol derivatives in excellent yield and with high diastereoselectivity. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:104–106, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20403     

Synthesis of cyclic aminomethylphosphonates and aminomethyl‐arylphosphinic acids by an efficient microwave‐mediated phospha‐mannich approach

Microwave‐assisted condensation of 1,3,‐2‐dioxaphosphinane 2‐oxide ( 1 ), paraformaldehyde and secondary amines including 5‐ and 6‐membered N‐heterocycles at 55°C gave cyclic aminomethylphosphonates ( 2 ), whereas an analogous reaction involving dibenzo[c.e][1,2]oxaphosphinane 2‐oxide ( 3 ) resulted in the corresponding aminomethyl‐2‐(2′‐hydroxybiphenyl)phosphinic acids ( 4 ) as a consequence of a hydrolytic ring opening following the condensation. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:207–210, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20387     

Some geometric properties of quantum phases and calculation of phase formulas

An introduction to several geometrical ideas which are of use to quantum mechanics is presented. The Aharonov‐Anandan phase is introduced and without reference to any dynamical equation, this phase is formulated by defining an appropriate connection on a specific fiber bundle. The holonomy element gives the phase. By introducing another connection, the Pancharatnam phase formula is derived following a different procedure. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008     

Oxidation using activated carbon and molecular oxygen system

This paper describes the utility of an activated carbon–molecular oxygen system, not only in the oxidation of benzylic and allylic alcohols, but also in the direct carbonylation at the benzylic position. The preparation of a variety of heteroaromatic and aromatic compounds, including substituted pyridines, pyrazoles, benzoxazoles, benzimidazoles, benzothiazoles, 2‐substituted imidazoles, indoles, pyrimidin‐2(1H)‐ones, and anthracenes, by oxidative aromatization using the activated carbon–molecular oxygen system is also discussed. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 252–267; 2008: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.20152     

Nucleophilic catalysis of phosphorus trichloride oxygen oxidation

The effect of nucleophilic catalysis on phosphorus trichloride oxygen oxidation is discovered. A number of nucleophilic catalysts for the phosphorus trichloride oxidation are found. Triethylamine, 4‐dimethylaminopyridine (DMAP), and tetramethylurea are amongst them. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:408–411, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20439