Unsaturated sulfonamides

Facile synthesis of optically active trifluoromethylated compounds asymmetric Diels-Alder reaction of trifluoromethylated ot, -unsaturated sulfonamide under high-pressure conditions [79]... 

Conformational analysis of a,/i-unsaturated sulfonamides based on ab initio calculations predicts a hinge-like molecular shape for the ground-state conformation. Following this lead, three chiral trifluoromethylated sulfonamides (133) were reacted with PhCOMe-LDA and CH2(C02Me)2-NaFl, respectively, to give the addition products (134) of up to 98% ee (Scheme 27).102... 

Ring-closing metathesis of the readily accessible doubly unsaturated sulfonamide 64 proceeded in the presence of the Grubbs catalyst in 53% yield to produce azocine 65 (Scheme 23 <1999JA8126>). 

Diastereoselective synthesis of homoallylic amines. The Diels-Alder adducts (2) formed from 1,3-dienes and 1 undergo basic hydrolysis to a single unsaturated sulfonamide (3) via a concerted rctro-cnc reaction. 

Table 3. Toxicity of Unsaturated Sulfonamides to Fire Ant Workers...

Cyclization. Intramolecular oxidative addition of an amidic nitrogen atom and a ip -hybridized carbon to a double bond is effected by the Cu(I) carboxylate. This type of reaction has been accomplished by Cu(OAc)2 on unsaturated sulfonamides. 

An investigation of the influence of high pressure versus temperature on induced diastereoselectivity was performed by Eguchi et al. for the cycloaddition of the a,/ -unsaturated sulfonamide (125) bearing a C2-symmetric chiral pyrrolidine auxiliary and cyclopentadiene (126) (Scheme 8.30) [61]. The same product ratio for 127 128 of 75 25 was found after 2 h at atmospheric pressure and 80 °C and after 14 h at... 

Scheme 8.30. Asymmetric Diels-Alder reaction of chiral trifluoromethylated unsaturated sulfonamides.

Scheme 15.42 Enantioselective bromoaminocyclisations of unsaturated sulfonamides to pyrrolidines.

Yeung et al. used amino-thiocarbamate catalysts 6 (Scheme 15.4), 8 and 9 derived from Cinchona alkaloids for enantioselective bromoaminocyclisa-tions of unsaturated sulfonamides to pyrrolidines (Scheme 15.42), 2-substituted 3-bromopyrolidines, and 2-substituted 3-bromopiper-idines in good yield and with high enantioselectivity. 

Unsaturated sulfonamides are recovered unchanged at temperatures normally required for ring closure and decompose at temperatures above 300 °C [669]. Allyl ureas decompose to give a large number of products [671]. Allyl urethanes react with hydrogenolysis of the C-N bond to form carbamates and a number of other products [671]. 

LiangJL, Yuan SX, HuangJS, Che CM. Intramolecular C—N bond formation reactions catalyzed by ruthenium porphyrins amidation of sulfamate esters and aziridination of unsaturated sulfonamides. J Org Chem. 2004 69 3610-3619. 

H. Me, Ph R = alkyl, alkenyl, atyl, heletoatyl Scheme 2.56. Synthesis of a, -unsaturated sulfonamides by the Peterson reaction. 

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