Sulphonyl isocyanates reactions

Loblolly pine modified by 1,6-diisocyanatohexane (HDI) was found to be resistant to attack by G. trabeum at a WPG of 26 % (Chen, 1992c). At 26 % WPG, 6 % of bonded chemical was lost during a 12-week soil decay test. When moist wood was used for reaction, the HDI reacted mainly to form ureas and biurets. It was stated that the decay resistance of HDI modified wood was probably due to the inability of the modified cell wall to absorb sufficient amounts of water to support decay. Although wood reacted with chloro-sulphonyl isocyanate lost only 1.3 % mass when exposed to G. trabeum in a decay test, it was reported that 50 % of the bonded chemical was lost in this test. 

The interaction of 1 with dipolar reagents has led to bridged norcaradienes (Section V.A.3) of varying stability , but with electrophilic C,V-diphenylnitrone ring expanded 123 is formed (Scheme 23) Similarly , reaction with sulphonyl isocyanates provides isoindolinones 124. Simple 1,3-dipoles such as methyl azidoformate and ethyl diazoacetate are without effect on 1, indicating too large an energy gap between the... 

Catalytic hydrogenation of the trimethyl phosphite-a-diketone adducts (76) gives the ketones (77) essentially quantitatively. The dioxaphospholan (78), obtained from the trimethyl phosphite-biacetyl adduct and isopropylidene-D-glyceraldehyde, has been converted into isomeric glycosides of l-deoxy-3-C-methyl-D-r/6o-hexulose. Another account has appeared of the reactions of (76) with aroyl and sulphonyl isocyanates."... 

The alternative [2 + 2] cycloaddition route to azetidinones, using chloro-sulphonyl isocyanate and functionalized alkenes, has been further used in syntheses of /8-lactam antibiotics. Asymmetric induction in the formation of /3-amino-aa-dimethyl-/8-phenylpropionic acid has been achieved, using a Reformatsky reagent and a chiral Schifif base, the reaction proceeding through a /3-lactam intermediate. ... 

Neooctams, such as the unsubstituted parent compound (191), are easily obtained in cycloadditions. Isocyanates [125,126], sulphonyl isocyanates (43) [29,127] and especially chlorosulphonyl isocyanate (189) [128] react with alkenes to form variously-substituted j3-lactams [129—135]. Synthesis of compound (191) is an example of this reaction which has been discussed in detail [52]. The same compound (192) can be obtained in the photolytic rearrangement of the pyrazolone (194) [136]. Compound (196) is neooctam-5,7-diene, obtained from the azocine (195) and hydrogen bromide [137]. Lactam (196)is a partly saturated form of (199). The latter is an unstable neooctam derivative, formed in an intramolecular ketene-imine cycloaddition reaction (see (198))... 

Sulphonyl Azides, Azosulphones, and Sulphonyl Isocyanates.— The particular interest in sulphonyl azides lies in their thermolysis into singlet sulphonylnitrenes, and the products of their reactions with the solvent thus alkylbenzenes and arenesulphonyl azides give azepines and aryl sulphonamides, anthracene gives sulphonamides via aziridines, and SjS-McjCjHjCHjCHjSOjNj gives a variety of intramolecular cyclization and intermolecular substitution products. ... 

The reactions of alcohols with sulphonyl isocyanates have been studied extensively in recent years and they are generally quite predictable those with 2-chloroethanol and 2-chloropropanoI are no exception. Substituted aryl isocyanates and isothiocyanates gave good yields of the carbamates, which on treatment with base afforded oxazolidin-2-ones and their thia-analogues. 

Protonation of the allenyl complex (16) with HPFg at — 20°C gives the cationic acetylene complex (17), and this observation, together with product stereochemistry, strongly suggests that the [2 + 3] cycloaddition reactions of (16) with tetracyanoethylene and toluene-p-sulphonyl isocyanate, which generate (18) and (19), respectively, proceed via an acetylene dipolar ion (20) rather than an allene (21). However, protonation of the related butynyl complex (22) generates stereospecifically a cationic allene complex (23), which on... 

The reactions of (Zi -allyl)iron and of cyclopropylmethyliron complexes with SOa and electrophilic olefins give cycloaddition products. The mechanisms of these reactions are considered to involve dipolar intermediates as illustrated in Scheme 4. These reactions have now been extended to cyclo-alkenyliron complexes, and it is found that toluene-p-sulphonyl isocyanate... 

Sulphimides.—(S)-(-)-2-Carboxyphenyl methyl N-toluene-p-sulphonyl sul-phimide (68 2-carboxyphenyl in place of Tol) may be prepared by the reaction of the corresponding sulphide with Chloramine-T, foUowed by conventional resolution, or from the optically active sulphoxide by reaction with NN -bis(toluene-p-sulphonyl)sulphur di-imide. " Acid-catalysed hydrolysis gives the sulphoxide with retention of configuration, and an-chimeric assistance by carboxylate is demonstrated, as for reactions of the sulphoxide itself. " (R)-(+)-Methyl-p-tolyl sulphoxide reacts with tol-uene-p-sulphonyl isocyanate to give the corresponding N-toluene-p-sulphonyl sulphimide (68) with net inversion, though product and recovered sulphoxide are partly racemized. The same sulphoxide reacts with toluene-... 

Finally, a sulphonyl nitrene has been suggested as a possible intermediate in the reaction of benzenesulphonyl isocyanate with phenylmagnesi-um bromide at room temperature, to account for the formation of a 13% yield of vV-phenylbenzenesulphonamide 47>. 

Chlorosulphonyl isocyanate, which normally reacts with olefins in a cryptoionic reaction to furnish as the major product a fi-lactam-N-sulphonyl chloride (75, 75 a), gives with longifolene on/j the unsaturated N-chlorosulphonylamide (123) (76). Reaction of longifolene with mercuric acetate-acetic acid followed by treatment with sodium chloride gives the vinyl derivative (124), besides other products (77). 

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