Synthesis,NMR‐Spectroscopy,and Molecular Structure of a Phosphonyl Ene Diamine

First examples of ene diamines with a phosphonate function at the C=C double bond were obtained by the reaction of dialkyl H‐phosphonates with bis(N‐tert‐butyl)‐diimine derived from glyoxal, [1,4‐bis(tert‐butyl)‐1,4‐diaza‐1,3‐butadiene], and isolated as hydrochlorides. Preferentially the cis‐diamine is formed. The new phosphonates are characterized by multinuclear NMR spectroscopy(¹H, ¹³C, ³¹P). In addition the methyl ester 8a was characterized by ^14,15N NMR spectroscopy as well as by several 2D NMR techniques and single‐crystal X‐ray diffraction, unequivocally establishing the ene diamine structure. In the crystal dimers of the cations are formed by P–O ··· H–N hydrogen bonding.     

Identification of tert‐Butyl Cations in Zeolite H‐ZSM‐5: Evidence from NMR Spectroscopy and DFT Calculations

Experimental evidence for the presence of tert‐butyl cations, which are important intermediates in acid‐catalyzed heterogeneous reactions, on solid acids has still not been provided to date. By combining density functional theory (DFT) calculations with ¹H/¹³C magic‐angle‐spinning NMR spectroscopy, the tert‐butyl cation was successfully identified on zeolite H‐ZSM‐5 upon conversion of isobutene by capturing this intermediate with ammonia.     

Synthesis and Fungicidal Activities of 2,3‐Dimethyl‐4‐(1‐acyloxy)alkoxy‐6‐tert‐butyl‐8‐fluoroquinolines

A series of 2,3‐dimethyl‐4‐(1‐acyloxy)alkoxy‐6‐tert‐butyl‐8‐fluoroquinolines were synthesized by 4‐(tert‐butyl)aniline as the starting material via acylation, substitution, and hydrolysis, and their structures were characterized by ¹H NMR, ¹³C NMR, and HRMS. The fungicidal activity showed that compounds 6c , 6e , and 6f had excellent activity against Sphoaerotheca fuliginea with EC₅₀ values of 38.62, 6.77, and 50.35 mg/L, respectively. The results suggest that this chemotype of compounds warrant further studies as promising fungicide.     

Synthese,Struktur, Elektrochemie und optische Eigenschaften von alkinylfunktionalisierten 1,3,2‐Diazaborolen und 1,3,2‐Diazaborolidinen

Syntheses, Structures, Electrochemistry and Optical Properties of Alkyne‐Functionalized 1,3,2‐Diazaboroles and 1,3,2‐Diazaborolidenes The reaction of 2‐bromo‐1,3‐ditert‐butyl‐2,3‐dihydro‐1H‐1,3,2‐diazaborole ( 3 ) with lithiated tert‐butyl‐acetylene and lithiated phenylacetylene affords the 2‐alkynyl‐functionalized 1,3,2‐diazaboroles 4 and 5 as a thermolabile colorless oil ( 4 ) or a solid ( 5 ). Similarly 2‐bromo‐1,3‐diethyl‐2,3‐dihydro‐1H‐1,3,2‐benzodiazaborole ( 6 ) was converted into the crystalline 2‐alkynyl‐benzo‐1,3,2‐diazaboroles 7 and 8 by treatment with LiC≡C–tBu or LiC≡CPh, respectively. 2‐Ethynyl‐1,3‐ditert‐butyl‐2,3‐dihydro‐1H‐1,3,2‐diazaborole ( 2 ) was metalated with tert‐butyl‐lithium and subsequently coupled with 2‐bromo‐1,3,‐ditert‐butyl‐2,3‐dihydro‐1H‐1,3,2‐diazaborole ( 3 ) to afford bis(1,3‐ditert‐butyl‐2,3‐dihydro‐1H‐1,3,2‐diazaborol‐2‐yl)acetylene ( 9 ) as thermolabile colorless crystals. Analogously coupling of the lithiated species with 6 or with 2‐bromo‐1,3‐ditert‐butyl‐1,3,2‐diazaborolidine ( 11 ) gave the unsymmetrically substituted acetylenes 10 or 12 , respectively, as colorless solids. Compounds 4 , 5 , 7 – 10 and 12 are characterized by elemental analyses and spectroscopy (IR, ¹H‐, ¹¹B{¹H}, ¹³C{¹H}‐NMR, MS). The molecular structures of 5 , 8 and 9 were elucidated by X‐ray diffraction analyses.     

A Macrobicyclic Calix[6]arene Phosphocine: Conformational Studies Involving High‐Resolution NMR Analysis and Molecular Modeling

The solution structure of the phosphorylated hexa(tert‐butyl)calix[6]arene 1a was elucidated through a series of high‐resolution, one‐ and two‐dimensional ¹H‐ and ¹³C‐NMR experiments, in combination with ³¹P‐NMR measurements. The NMR results were cross‐checked and refined with partial structural information obtained from a poorly resolved X‐ray crystal‐structure analysis. The latter, that could not be upgraded due to the low quality of the crystals and due to strong thermal motions, confirmed that 1a was a racemate in which two adjacent phenol units are bridged by a mono‐ethyl phosphate moiety, generating a macrocyclic dibenzo[1,3,2]dioxaphosphocine substructure, while the four residual aromatic rings bear regular diethyl phosphate arms. One of these rings is inverted, generating the main asymmetry in the molecule, which gives rise to the racemic nature of the macrobicycle. The two enantiomers, however, do not interconvert on the NMR time scale in solution and resemble the solid‐state structure, as expected from the steric hindrance due to the pendant phosphoesters and the high intramolecular tension due to the presence of the phosphocine substructure. The most‐probable conformation of 1a in solution was determined, starting from the NMR and X‐ray data, by means of semi‐empirical PM3 calculations with the GEOMOS program, including an unprecedented large number of 232 atoms.     

Synthesis of anionic hypervalent cyclic selenenate esters: relevance to the hypervalent intermediates in nucleophilic substitution reactions at the selenium(II) center

The synthesis of a diaryl diselenide that contains 2,6‐dicarboxylic acid groups, 2,2′‐diselanediylbis(5‐tert‐butylisophthalic acid) ( 10 ), is described. Diselenide 10 undergoes intramolecular cyclization in methanol to form a cyclic selenenate ester, 5‐tert‐butyl‐3‐oxo‐3H‐benzo[c][1,2]oxaselenole‐7‐carboxylic acid ( 11 ). The cyclization reaction proceeds more rapidly in the presence of organic bases, such as pyridine, adenine, and 4,4′‐bipyridine, to form pyridinium 5‐tert‐butyl‐3‐oxo‐3H‐benzo[c][1,2]oxaselenole‐7‐carboxylate ( 14 ), adeninium 5‐tert‐butyl‐3‐oxo‐3H‐benzo[c][1,2]oxaselenole‐7‐carboxylate ( 15 ), and 4,4′‐bipyridiniumbis(5‐tert‐butyl‐3‐oxo‐3H‐benzo[c][1,2]oxaselenole‐7‐carboxylate) ( 16 ), respectively. However, 2,2′‐diselanediyldibenzoic acid ( 22 ) does not undergo cyclization under similar conditions. Structural studies on cyclic selenenate esters 14 – 16 revealed that the Se???O (COO^?) secondary distances (2.170, 2.075, and 2.176 Å) were significantly shorter than the corresponding Se???O distances (2.465, 2.472, and 2.435 Å) observed for the selenenate esters stabilized by the neutral donors (CHO, COOH, and COOEt). ¹H, ¹³C, and ⁷⁷Se NMR spectroscopy of compounds 11 and 14 – 16 reveal that the aryl protons of compound 11 and the organic cations of compounds 14 – 16 exchange between the two carboxylate groups via a hypercoordinate intermediate. The corresponding hypercoordinate intermediate ( 14 b , pyridinium selenuranide) for compound 14 was detected at low temperatures using ⁷⁷Se NMR spectroscopy. The presumed hypercoordinate intermediates in the carboxylate‐exchange reactions at the selenium(II) center for a set of model reactions were optimized using DFT‐B3LYP/6–311+g(d) calculations and their structural features compared with the X‐ray structure of anionic selenenate esters 14 – 16 .     

A New Route for the Modification of Halogen End Groups to Amino End‐Functionalized Poly(tert‐butyl acrylate)s

The synthesis of primary amine end‐functional poly(tert‐butyl acrylate)s has been achieved by using the Gabriel reaction. Polymerization of tert‐butyl acrylate was first achieved by atom transfer radical polymerization using ethyl‐2‐bromoisobutyrate or paramethoxyphenyl‐2‐bromoisobutyrate as initiator. Both resulting polymers, with a bromide‐end atom, were converted into phthalimido intermediates which then were successfully hydrolyzed using potassium hydroxide in tert‐butyl alcohol to result in poly(tert‐butyl acrylate)s terminated by a primary amine function. End group interconversions were followed by ¹H NMR, FT‐IR, and MALDI‐TOF MS measurements. All the results proved that quantitative transformations were achieved at each step. Moreover, the method developed is very easy to carry out.

     

1,3‐Bis(trimethylsilyl)‐1,3,2‐diazaphospha‐[3]ferrocenophanes

The 2‐tert‐butyl, 2‐phenoxy, and 2‐diethylamino derivatives of 1,3‐bis(trimethylsilyl)‐1,3,2‐diazaphospha‐[3]ferrocenophane were prepared, and the molecular structure of the latter was determined by X‐ray diffraction. The phosphines could be oxidized by their slow reactions with sulfur or selenium, and the molecular structures of three sulfides and one selenide were determined. In contrast, the synthesis of oxides was less straightforward. All new compounds were characterized in solution by multinuclear magnetic resonance methods (1D and 2D ¹H, ¹³C, ¹⁵N, ²⁹Si, ³¹P, and ⁷⁷Se NMR spectroscopy).     

Synthesis of triblock copolymers based on two isomer acrylate monomers by atom transfer radical polymerization

The syntheses of triblock copolymers by the atom transfer radical polymerization of tert‐butyl and iso‐butyl acrylates as inner blocks with cyclohexyl methacrylate as outer blocks are reported. The living behavior and blocking efficiency of these polymerizations were investigated in each case. The use of difunctional macroinitiators led to ABA triblock copolymers with narrow polydispersities and controlled number‐average molecular weights. These copolymers were prepared from bromo‐terminated macroinitiators of poly(tert‐butyl acrylate) and poly(iso‐butyl acrylate), with copper chloride/N,N,N′,N″,N″‐pentamethyldiethylenetriamine as the catalytic system, at 40 °C in 50% (v/v) toluene solutions. The block copolymers were characterized with size exclusion chromatography and ¹H NMR spectroscopy. Differential scanning calorimetry measurements were performed to reveal the phase segregation. The glass transition of the inner block was not clearly detected, with the exception of the copolymer synthesized with the longest poly(iso‐butyl acrylate) macroinitiator length. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4828–4837, 2005     

Synthesis and characterization of biodegradable triblock copolymers based on bacterial poly[(R)‐3‐hydroxybutyrate] by atom transfer radical polymerization

Biodegradable poly(tert‐butyl acrylate)–poly[(R)‐3‐hydroxybutyrate]–poly (tert‐butyl acrylate) triblock copolymers based on bacterial poly[(R)‐3‐hydroxybutyrate] (PHB) were synthesized by atom transfer radical polymerization. The chain architectures of the triblock copolymers were confirmed by ¹H NMR and ¹³C NMR spectra. Gel permeation chromatography analysis was used to estimate the molecular weight characteristics and lengths of the PHB and poly(tert‐butyl acrylate) blocks of the copolymers. The thermal properties of the copolymers were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA showed that the triblock copolymers underwent stepwise thermal degradation and had better thermal stability than their respective homopolymers, whereas DSC analyses showed that a microphase‐separation structure was formed only in the triblock copolymers with the longer PHB block. As a similar result, from wide‐angle X‐ray diffraction experimentation, the crystalline phase of PHB could not be seen evidently in the triblock copolymers with the shorter PHB block. The enzymatic hydrolysis of the copolymer films was carried at 37 °C and pH 7.4 in a potassium phosphate buffer with an extracellular PHB depolymerase from Penicillum sp. The biodegradability of the triblock copolymers increased with an increase in the PHB block content. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4857–4869, 2005     

Chiral Iridium Spiro Aminophosphine Complexes: Asymmetric Hydrogenation of Simple Ketones,Structure, and Plausible Mechanism

The iridium complexes of chiral spiro aminophophine ligands, especially the ligand with 3,5‐di‐tert‐butylphenyl groups on the P atom ( 1c ) were demonstrated to be highly efficient catalysts for the asymmetric hydrogenation of alkyl aryl ketones. In the presence of KOtBu as a base and under mild reaction conditions, a series of chiral alcohols were synthesized in up to 97 % ee with high turnover number (TON up to 10 000) and high turnover frequency (TOF up to 3.7×10⁴ h⁻¹). Investigation on the structures of the iridium complexes of ligands (R)‐ 1a and 1c by X‐ray analyses disclosed that the 3,5‐di‐tert‐butyl groups on the P‐phenyl rings of the ligand are the key factor for achieving high activity and enantioselectivity of the catalyst. Study of the catalysts generated from the Ir‐(R)‐ 1c complex and H₂ by means of ESI‐MS and NMR spectroscopy indicated that the early formed iridium dihydride complex with one (R)‐ 1c ligand was the active species, which was slowly transformed into an inactive iridium dihydride complex with two (R)‐ 1c ligands. A plausible mechanism for the reaction was also suggested to explain the observations of the hydrogenation reactions.     

Synthesis of polar block grafted syndiotactic polystyrenes via a combination of iridium‐catalyzed activation of aromatic C?H bonds and atom transfer radical polymerization

A combination of iridium‐catalyzed C H activation/borylation and atom transfer radical polymerization (ATRP) was used to generate polar graft copolymers of syndiotactic polystyrene (sPS). The borylation at aromatic C H bonds of sPS and subsequent oxidation of boronate ester proceeded without negatively affecting the molecular weight properties and the tacticity of sPS. A macroinitiator suitable for ATRP could be synthesized by the esterification of 2‐bromo‐2‐methylpropionyl bromide and hydroxy‐functionalized sPS. The graft polymerizations of methyl methacrylate and tert‐butyl acrylate from the macroinitiator using ATRP afforded polar block grafted sPS materials, syndiotactic polystyrene‐graft‐poly(methyl methacrylate) (sPS‐g‐PMMA) and syndiotactic polystyrene‐graft‐poly(tert‐butyl acrylate) (sPS‐g‐PtBA). The latter was hydrolyzed to yield an amphiphilic graft copolymer, syndiotactic polystyrene‐graft‐poly(acrylic acid) (sPS‐g‐PAA). The structures of the copolymers were characterized by NMR and FTIR spectroscopies. Size exclusion chromatography and ¹H NMR spectroscopy were used to study any changes in the molecular weight properties from the parent polymer. A decrease in the hydrophobicity of the graft copolymers was confirmed by water contact angle measurements. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6655–6667, 2009     

Copper(II)‐Mediated Transformation of a Tridentate Non‐Innocent Ligand into a Tetradentate Salen‐Type Innocent Ligand

A non‐innocent ligand, H₄L, was synthesized by introducing a ? CH₂NH₂ group at the ortho carbon atom to the aniline moiety of 2‐anilino‐4,6‐di‐tert‐butylphenol. The new ligand was characterized by IR and NMR spectroscopy and mass spectrometry techniques. Upon treatment with CuCl₂ ? 2 H₂O, this non‐innocent ligand provided a mononuclear four‐coordinate salen‐type Cu^II complex by complete modification of the ligand backbone. The complex was characterized by IR spectroscopy, mass spectrometry, X‐ray single‐crystal diffraction, electron paramagnetic resonance (EPR) spectroscopy, and UV/Vis/near‐IR spectroscopy techniques. X‐ray crystallographic analysis showed an asymmetric environment around the Cu^II center with a small (≈12°) twist between the two biting planes. Analysis of the X‐band EPR spectrum also supported the asymmetric environment and also indicated the presence of an unpaired electron on the d orbital. The UV/Vis/near‐IR spectrum showed strong absorption bands for metal‐to‐ligand charge transfer and ligand‐to‐metal charge transfer along with a Cu^II‐centered d–d transition. Mechanistic investigation of the formation of complex 1 indicated that modification of the ligand backbone proceeded through ligand‐centered amine to imine oxidation as well as through C? N bond‐breaking processes. During these processes, 3,5‐di‐tert‐butyl‐1,2‐benzoquinone and 2‐aminobenzylidene were produced. Ammonia, generated in situ through hydrolysis of the imine to the aldehyde, reacted with 3,5‐di‐tert‐butyl‐1,2‐benzoquinone to form the corresponding 3,5‐di‐tert‐butyl‐1,2‐iminobenzoquinone moiety, which upon two‐electron reduction in the reaction medium formed 3,5‐di‐tert‐butyl‐1,2‐aminophenol. This aminophenol underwent condensation with the H₂L5 ligand that was formed by self‐condensation of two molecules of 2‐aminobenzaldehyde and provided the modified ligand backbone.     

Stable trans isomer as the kinetic and theromodynamic product for the oxidative addition of MeI to cycloplatinated(II) complexes comprising isocyanide ligands

The present investigation introduces a new series of cycloplatinated(II) complexes, with the general formula Pt(O‐bpy)(Me)(CN‐R)] (R = benzyl, 2‐naphtyl and tert‐butyl), which are able to generate the stable trans‐Pt(IV) product in the solution after the reaction with iodomethane. In fact, the trans product is both the kinetic and thermodynamic product of the reaction; this observation was supported by DFT calculations. These Pt(II) complexes are supported by 2,2'‐bipyridine N‐oxide (O‐bpy) and one of several isocyanides as the cyclometalated and ancillary ligands, respectively. These new Pt(II) complexes undergo oxidative addition with MeI to give the corresponding trans‐Pt(IV) complexes. All the complexes were identified employing the multi‐nuclear NMR spectroscopy and single crystal X‐ray crystallography. The kinetic investigations were also performed for the oxidative addition reactions in order to measure the reaction rates; the reaction was followed by UV‐Vis spectroscopy. The rates obtained follow the trend CN‐^tBu > CN‐Bz > CN‐2 Np for the CN‐R ligands in the Pt(II) complexes. The order can be related to the degree of electron‐donation of the R group (tert‐butyl > benzyl > 2‐naphtyl).     

Synthesis of end‐functionalized polyethers by phosphazene base‐catalyzed ring‐opening polymerization of 1,2‐butylene oxide and glycidyl ether

For the living ring‐opening polymerization (ROP) of epoxy monomers, the catalytic activity of organic superbases, tert‐butylimino‐tris(dimethylamino)phosphorane, 1‐tert‐butyl‐2,2,4,4,4‐pentakis(dimethylamino)‐2Λ⁵,4Λ⁵‐catenadi(phosphazene), 2,8,9‐triisobutyl‐2,5,8,9‐tetraaza‐1‐phosphabicyclo[3.3.3]undecane, and 1‐tert‐butyl‐4,4,4‐tris(dimethylamino)‐2,2‐bis[tris(dimethylamino)phosphoranylidenamino]‐2Λ⁵,4Λ⁵‐catenadi(phosphazene) (t‐Bu‐P₄), was confirmed. Among these superbases, only t‐Bu‐P₄ showed catalytic activity for the ROP of 1,2‐butylene oxide (BO) to afford poly(1,2‐butylene oxide) (PBO) with predicted molecular weight and narrow molecular weight distribution. The results of the kinetic, post‐polymerization experiments, and MALDI‐TOF MS measurement revealed that the t‐Bu‐P₄‐catalyzed ROP of BO proceeded in a living manner in which the alcohol acted as the initiator. This alcohol/t‐Bu‐P₄ system was applicable to the glycidol derivatives, such as benzyl glycidyl ether (BnGE) and t‐butyl glycidyl ether, to afford well‐defined protected polyglycidols. The α‐functionalized polyethers could be obtained using different functionalized initiators, such as 4‐vinylbenzyl alcohol, 5‐hexen‐1‐ol, and 6‐azide‐1‐hexanol. In addition, the well‐defined cyclic‐PBO and PBnGE were successfully synthesized using the combination of t‐Bu‐P₄‐catalyzed ROP and click cyclization. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Synthesis of poly(N‐[tris(hydroxymethyl)methyl]acrylamide) functionalized porous silica for application in hydrophilic interaction chromatography

Porous silica coated by a highly hydrophilic and nonionic tentacle‐type polymeric layer was synthesized by free radical “grafting from” polymerization of N‐[2‐hydroxy‐1,1‐bis(hydroxymethyl)ethyl]‐2‐propenamide (TRIS‐acrylamide) in partly aqueous solutions. The radical initiator sites were incorporated on the silica surfaces via a two‐step reaction comprising thionyl chloride activation and subsequent reaction with tert‐butyl hydroperoxide. The surface‐bound tert‐butylperoxy groups were then used as thermally triggered initiators for graft polymerization of TRIS‐acrylamide. The synthesized materials were characterized by diffusive reflectance Fourier transform infrared specotroscopy, X‐ray photoelectron spectroscopy, and CHN elemental analysis. Photon correlation spectroscopy was used to determine changes in ζ‐potentials resulting from grafting, ²⁹Si magic angle spinning nuclear magnetic resonance spectroscopy (MAS‐NMR) spectroscopy was used to assess the ratio of silanol to siloxane groups in the substrate and the grafted material, and the changes in surface area and mesopore distribution were determined by nitrogen cryosorption. Chromatographic evaluation in hydrophilic interaction chromatography (HILIC) mode showed that the materials were suitable for use as stationary phases, featuring good separation efficiency, a comparatively high retention, and a selectivity that differed from most commercially available HILIC phases. A comparison of this neutral phase with a previously reported N‐(2‐hydroxypropyl)‐linked TRIS‐type hydrophilic tentacle phase with weak anion exchange functionality revealed substantial differences in retention patterns.     

Dibutylsilylene Derivatives of Tartaric Acid

Crystals of the bis(tert‐butyl)silylene (DTBS) derivatives of the tartaric acids were synthesized from D ‐, L ‐, rac‐, and meso‐tartaric acid and DTBS bis(trifluoromethanesulfonate): two polymorphs of Si₂tBu₄(L ‐Tart1,2;3,4H_–4) (L ‐ 1a and L ‐ 1b ), the mirror image of the denser modification (D ‐ 1b ) as well as the racemate ( 2 ), and the meso analogue Si₂tBu₄(meso‐Tart1,3;2,4H_–4) ( 3 ). The structures were determined by single‐crystal X‐ray diffraction. The threo‐configured D ‐ and L ‐ (and rac‐) tartrates were coordinated by two tBu₂Si units forming five‐membered chelate rings, whereas the erythro‐configured meso‐tartrate formed six‐membered chelate rings. The new compounds were analyzed by NMR techniques, including ²⁹Si NMR spectroscopy, and single‐crystal X‐ray crystallography.     

Conformational Switching of Resorcin[4]arene Cavitands by Protonation,Preliminary Communication

The synthesis of the quinoxaline‐bridged resorcin[4]arene cavitand 1 was accomplished from 2‐[3,5‐di(tert‐butyl)phenyl]acetaldehyde via formation of the intermediate octol 2 . Such cavitands are known to occur in an open `kite' conformation at low temperature (<213 K) but to adopt a `vase' conformation at elevated temperatures (>318 K). We discovered that protonation of cavitand 1 at room temperature by common acids, such as CF₃COOH, also causes reversible switching from `vase' to `kite', and that this conformational change can be conveniently monitored by both ¹H‐NMR and UV/VIS spectroscopy.     

New Aspects of 1,3‐Diphosphacyclobutane‐2,4‐diyls

1,3‐Di(tert‐butyl)‐2,4‐bis[2,4,6‐tri(tert‐butyl)phenyl]‐1,3‐diphosphacyclobutane‐2,4‐diyl was formed from [2,4,6‐tri(tert‐butyl)phenyl]phosphaacetylene and t‐BuLi. In addition, the X‐ray diffraction analysis was carried out, together with theoretical calculations of the structure and NMR data.     

Attempt to Synthesize Hindered 2,4,6‐Tri‐Aryloxy‐s‐Triazines: Bis(2,4‐di‐tert‐Butylphenyl) Carbonate – Crystal Structure

Some less hindered 2,4,6‐tri‐aryloxy‐s‐triazines were synthesized through the reaction of the corresponding phenols as a starting materials with cyanogen bromide (BrCN) to obtain the corresponding arylcyanates and then trimerized. Unexpectedly, 2,4‐di‐tert‐butyl‐1‐cyanatobenzene derived from 2,4‐di‐tert‐butylphenol did not trimerize but, indeed, yielded bis(2,4‐di‐tert‐butylphenyl) carbonate. The structures of 2,4,6‐tri‐aryloxy‐s‐triazines and bis(2,4‐di‐tert‐butylphenyl) carbonate were characterized by means of IR, ¹H, and ¹³C NMR spectroscopies. Also the structure of the latter compound was studied by X‐ray crystallography.