Copper-catalyzed cyanation of aryl iodide with the combined cyanide source of urea and DMSO

A simple copper-catalyzed cyanation of aryl iodide with the combination of urea and dimethyl sulfoxide as a cyanide source is achieved, providing nitriles in moderate to good yields. This new approach represents an exceedingly practical and safe method for the synthesis of aryl nitriles.     

Synthesis of cyanofuroxans from 4-nitrofuroxans via CC bond forming reactions

A substitution reaction of 4-nitrofuroxans to prepare 4-cyanofuroxans is described. This substitution reaction was complicated by the reverse reaction and a judicious choice of cyanide source was important to enable this direct synthesis process. The optimized reaction conditions showed an excellent applicability for the synthesis of a range of 4-cyanofuroxans. 3-Cyanofuroxans, known to be thiol-mediated nitric oxide donors, could also be obtained by the thermal or photochemical isomerization of 4-cyanofuroxans. The developed cyanation of furoxans is a rare example of CC bond-forming reaction on a furoxan ring.     

An efficient and facile one-pot synthesis of cyanohydrin esters from carbonyl compounds catalyzed by iron(III) chloride

A variety of cyanohydrin esters were readily prepared from carbonyl compounds with trimethylsilyl cyanide and acid anhydride under the influence of a catalytic amount of iron(III) chloride in a convenient one-pot procedure.     

Iron(III) triflate-catalyzed one-pot synthesis of acetal-type protected cyanohydrins from carbonyl compounds

A variety of cyanohydrin THP ethers were readily prepared from carbonyl compounds with trimethylsilyl cyanide and tetrahydropyran-2-yl acetate under the influence of a catalytic amount of iron(III) triflate in a convenient one-pot procedure. This method was also effective to prepare O-protected cyanohydrins by various acetal-type protective groups.     

Palladium bis(2,2,6,6-tetramethyl-3,5-heptanedionate) catalyzed Suzuki, Heck, Sonogashira, and cyanation reactions

Palladium bis(2,2,6,6-tetramethyl-3,5-heptanedionate): a structurally well-defined O-containing transition metal complex is reported as an efficient catalyst for Suzuki, Heck, and Sonogashira cross-coupling reactions. The protocol was also applied successfully for cyanation of aryl halides under milder operating conditions. The system tolerated the coupling of various aryl halides with alkenes, alkynes, and organoboronic acid along with the cyanation of aryl halides providing good to excellent yields of desired products.     

InBr3-catalyzed stereoselective synthesis of trans-2,6-disubstituted 3,6-dihydro-2H-pyrans

A new method for the stereoselective synthesis of trans-2,6-disubstituted 3,6-dihydro-2H-pyrans with a variety of substitution patterns is described, involving Lewis acid induced tandem allylation or cyanation of δ-hydroxy-α,β-unsaturated aldehydes to produce dihydropyrans in good yields and with trans-selectivity. This method is very useful for the synthesis of trans-2,6-disubstituted dihydropyran ring-containing natural products such as laulimalide, scytophycin C and many others.     

Indole cyanation via C-H bond activation under catalysis of Ru(Ⅲ)-exchanged NaY zeolite(RuY) as a recyclable catalyst

Selective 3-cyanation of indoles was achieved under heterogeneous catalysis of Ru(Ⅲ)-exchanged NaY zeolite(RuY) as a recyclable catalyst,in combination with K 4 [Fe(CN) 6 ] as a nontoxic,slow cyanide releasing agent.Under the aforementioned conditions,good yields of the desired products were obtained.     

C3-Cyanation of Pyridines: Constraints on Electrophiles and Determinants of Regioselectivity

Methods for C−H cyanation of pyridines are rare. Here, we report a method for C3-selective cyanation of pyridines by a tandem process with the reaction of an in situ generated dihydropyridine with a cyano electrophile as the key step. The method is suitable for late-stage functionalization of pyridine drugs. The low reduction potential of the electrophile and effective transfer of the nitrile group were found to be essential for the success of this method. We studied the reaction mechanism in detail by means of control experiments and theoretical calculations and found that a combination of electronic and steric factors determined the regioselectivity of reactions involving C2-substituted pyridines.