Aryl halides amines without additives

Reactions of aryl halides with amines without additives. 502... 

Linstrumelle and co-workers reported that vinyl and aryl halides or triflates react very rapidly with terminal alkynes, without addition of copper salt, and lead to high yields of eneynes and aryl acetylenes by using Pd(PPh3)4 as a catalyst. The nature of the amine is critical for the success of the coupling (Scheme 3, [Pd] I). However,... 

Zeolites are very useful catalysts for a large variety of reactions, from acid to base and redox catalysis [27]. Hutchings et al. reported that bis(oxazoline)-modified Cu (II)-HY catalysts are effective for asymmetric carbonyl- and imino-ene reactions and aziridination of styrene [28, 29]. Recently Djakovitch and Kohler [30-34] found that Pd(II)-NaY zeolite activates aryl halides towards Heck olefination, a-arylation of malonate, and amination reactions. It is well known that alkali-exchanged faujasite zeolites are solid base catalysts [35]. Owing to the usefulness of zeolites in organic chemistry, and our interest, we recently reported the use of modified alkali-exchanged zeolite Y, NaY zeolite [36] with electron rich copper catalyst in the Y-arylation of nitrogen heterocycles with aryl halides to afford A -arylheterocycles in excellent yields under mild conditions without the use of any additive. 

In summary, sulfonamides are most commonly prepared by the reaction of amines with sulfonyl halides. Aryl sulfonyl chlorides may be accessed from C-H bonds by chlorosulfonylation, from C-S bonds by oxidation, from C-N bonds by diazotization, or from C-X bonds by metalation. Approaches to all l sulfonamides are more limited as they are typically prepared by either oxidative chlorination of thiols or addition of organometallic nucleophiles to sulfur electrophiles. Traditional sulfonamide preparation has frequently necessitated harsh reagents and conditions, but the development of Pd-catalysed approaches and discovery of new sulfur dioxide sources allow for operationally simple sulfonamide synthesis under mild conditions. Future directions in sulfonamide synthesis will likely involve the direct C-H installation of sulfonamides without the use of hazardous reagents. 

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