F. Vinyl Sulfones and Other Michael Acceptors 4683 G. Azodicarboxamides 4695 IV. Acylating Agents 4695 A. Aza-peptides 4695 B. Carbamates 4699 C. Peptidyl Acyl Hydroxamates 4700 D. â-Lactams and Related Inhibitors 4704 E. Heterocyclic Inhibitors 4714 1. Isocoumarins 4715 2. Benzoxazinones 4722 3. Saccharins 4725 4. Miscellaneous Heterocyclic Inhibitors 4728 V. Phosphonylation Agents 4728 A. Peptide Phosphonates 4728 B. Phosphonyl Fluorides 4734 VI. Sulfonylating Agents 4735 A. Sulfonyl Fluorides 4735 VII. Miscellaneous Inhibitors 4736 VIII. Summary and Perspectives 4737 IX. Acknowledgments 4740 X. Note Added in Proof 4740 XI. References 4740

Irreversible inhibitors of serine, cysteine, and threonine proteases.

Several 3-halo-3-(1-haloalkyl)-1(3H)-isobenzofuranones, 3-(1-haloalkylidene)-1(3H)-isobenzofuranones, and 3-bromomethyl-1H-2-benzopyran-1-ones containing masked halo ketone functional groups were synthesized and tested as inhibitors of several serine proteases including human leukocyte (HL) elastase and cathepsin G While many of the 3-halo-3-(1-haloalkyl)-1(3H)-isobenzofuranones were quite potent inhibitors of the enzymes tested, the alkylideneisobenzofuranones and benzopyran-1-ones inhibited poorly or not at all The 3-halo-3-(1-haloalkyl)-1(3H)-isobenzofuranones decomposed rapidly upon addition to buffer to give the corresponding 3-alkyl-1H-2-benzopyran-1,4(3H)-diones The pure benzopyran-1,4-diones were extremely potent inhibitors of HL elastase and chymotrypsin A alpha but did not inactivate porcine pancreatic elastase or cathepsin G Enzymes inhibited by the isobenzofuranones and benzopyran-1,4-diones regained activity slowly upon standing or after dialysis (t1/2 = 5-16 h) and more rapidly in the presence of 05 M hydroxylamine, which indicated the presence of labile acyl moieties in the inhibited enzyme These results are consistent with a scheme in which the active site serine of the protease reacts with the lactone carbonyl of these inhibitors to give a stable acyl enzyme and alkylation of another active site residue by the unmasked halo ketone functional group does not occur

Inhibition of human leukocyte elastase, cathepsin G, chymotrypsin A alpha, and porcine pancreatic elastase with substituted isobenzofuranones and benzopyrandiones.

Enzyme models. The attachment of N-methylhydroxamic acid to cyclohexaamylose. Its reactivity and specificity with phenyl esters

Synthese sowie thermisches und photochemisches Verhalten der spezifisch deuterierten 2-Diazopropan- und 2-Diazo-1-methoxypropan-Addukte des 1,3-Cyclobutadiens [1-D]-1a, [1-D]-1b und [1-D]-1c werden beschrieben. Sowohl die photochemisch als auch thermisch induzierte N2-Eliminierung aus [1-D]-1a fuhrt zu einem 1 : 1-Gemisch der regioisomeren Bicyclo[2.1.0]pentene [1-D]-3a und [2-D]-3a bzw. der als Folgeprodukte gebildeten Cyclopentadiene [1-D]-12a und [2-D]-12a. Durch Photolyse der diastereomeren Addukte [1-D]-1b und [1-D]-1c wird festgestellt, das nach der N2-Abspaltung beide Ringschlusreaktionen zum Bicyclo[2.1.0]penten-System zwischen C-5 und C-1 sowie C-5 und C-3 stereospezifisch mit Retention an C-5 ablaufen. Zur Erklarung der Ergebnisse wird das Diradikal [1-D]-2b bzw. -2c als Ubergangszustand der Cyclisierungsreaktionen postuliert. Die Beobachtung, das die „walk”-Umlagerung in Bicyclo[2.1.0]penten mit Inversion an C-5 erfolgt, schliest fur diesen Prozes die Beteiligung eines Diradikals vom Typ 2 aus.



Mechanism of the Cyclopropane “walk” Rearrangement: Syntheses and Properties of Diazoalkane Adducts of 1,3-Cyclobutadiene



The synthesis and the thermal and photochemical behaviour of the specifically deuterated 2-diazopropane- and 2-diazo-1-methoxypropane adducts of 1,3-cyclobutadiene [1-D]-1a, [1-D]-1b, and [1-D]-1c are reported. The elimination of N2 in [1-D]-1a photochemically as well as thermally induced leads to a 1 : 1 mixture of the regioisomeric bicyclo[2.1.0]-pentenes [1-D]-3a and [2-D]-3a or cyclopentadienes [1-D]-12a and [2-D]-12a formed as secondary products. Photolysis of the diastereomeric adducts [1-D]-1b and [1-D]-1c reveals that after extrusion of N2 each ring closure reaction between C-5 and C-1 or C-5 and C-3 gives the corresponding bicyclo[2.1.0]pentene system stereospecifically with retention at C-5. Diradicals [1-D]-2b and -2c are postulated to be the transition states of the cyclisation reactions. The observation that the “walk” rearrangement in the bicyclo[2.1.0]pentene system proceeds with inversion at C-5 rules out the participation of a diradical of type 2 in this process.

Zum Mechanismus der Cyclopropan‐„walk”︁‐Umlagerung: Synthese und Eigenschaften von Diazoalkan‐Addukten des 1,3‐Cyclobutadiens

This chapter is organized on the basis of a classification of sulfonate and sulfate esters according to the nature and number of the alcohols from which they are derived. In the case of the sulfate esters, the reason for this mode of organization is obvious. However, in treating the chemistry of the sulfonate esters, we could have used the nature of the parent sulfonic acids as the basis for the organization of our discussion. We did not do this for two reasons. One is that we wished to present a reasonably parallel treatment of the chemistry of sulfonate and sulfate esters. The other is that we felt that, from a mechanistic standpoint, reactivity patterns emerge most clearly when the reactions of sulfonate esters are examined in terms of the kinds of alcohol groups which can be displaced.

Reactions of Sulfonate and Sulfate Esters

Readily reversible nucleophilic reaction of imidazole with .beta.-(2-hydroxy-3,5-dinitrophenyl)ethanesulfonic acid sultone

Desulfonylation of 2-hydroxy-3,5-dinitro-.alpha.-toluenesulfonyl-.alpha.-chymotrypsin

Studies on the desulfonylation of 2-hydroxy-3,5-dinitro-alpha-toluenesulfonyl-alpha-chymotrypsin

Die reversible nucleophile rk. von imidazol mit beta-(2-hydroxy-3,5-dinitro-phenyl)-aethansulfonsaeuresulton

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Readily reversible nucleophilic reaction of imidazole with .beta.-(2-hydroxy-3,5-dinitrophenyl)ethanesulfonic acid sultone

Desulfonylation of 2-hydroxy-3,5-dinitro-.alpha.-toluenesulfonyl-.alpha.-chymotrypsin

Studies on the desulfonylation of 2-hydroxy-3,5-dinitro-alpha-toluenesulfonyl-alpha-chymotrypsin

Die reversible nucleophile rk. von imidazol mit beta-(2-hydroxy-3,5-dinitro-phenyl)-aethansulfonsaeuresulton