Iron-Catalyzed Asymmetric Decarboxylative Azidation

Abstract

The first iron-catalyzed asymmetric azidation of benzylic peresters has been reported with trimethylsilyl azide (TMSN3) as the azido source. Hydrocarbon radicals that lack of strong interactions were capable to be enantioselectively azidated. The reaction features good functional group tolerance, high yields, and mild conditions. The chiral benzylic azides can further be used in click reaction, phosphoramidation, and reductive amination, which demonstrate the synthetic values of this reaction.

Enantioselective catalytic radical decarbonylative azidation and cyanation of aldehydes

“…On the basis of all evidences from the aforementioned experiments and previous reports (38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54), a plausible mechanism involving a Fe(II)/ Fe(III) catalytic cycle for the azidation and Cu(I)/ Cu(II)-catalyzed cyanation was proposed as shown in Fig. 5D.…”

“…Moreover, decarboxylative enantioselective functionalization of carboxylic acids through a SET process has emerged as a powerful strategy for the construction of C─C bond or C─X bond (33)(34)(70)(71)(72)(73)(74). However, in many known reports, especially in the copper-catalyzed enantioselective decarboxylative cyanation and iron-catalyzed enantioselective decarboxylative azidation, preactivation of the carboxylic acid to a redox-active substrate is generally required, such as preparation of N-hydroxyphthalimide ester (34,47), benzylic perester (54), or in situ generation of carboxyl iodine(III) species (75)(76)(77), which reduces the atom economy and limits the tolerance of functional groups. Recently, several examples on copper-catalyzed asymmetric decarboxylative cyanation of benzylic acids based on photoelectrocatalytic strategies have been developed (78-80) but require photo-and electrochemical reactors in the experimental design.…”

Lewis Acid Catalyzed Three‐Component Carbofunctionalization of Styrenes with Diacyl Peroxides and Nucleophiles

“…Recently, diacyl peroxides, another type of activated carboxylic acids, could use as both alkylating reagents and internal oxidants in radical decarboxylative cross‐coupling [8] . Bao's group developed a series of excellent works in this field, [8a–e] for example, they reported the first iron‐catalyzed alkylamination of alkene with diacyl peroxides and acetonitrile (Scheme 1b), providing a straightforward way for the synthesis of complex functionalized amines [8e] . However, limited nitrogen sources and additional hydrolysis process could compromise its wider application.…”

Thermo-induced decarboxylative α-C(sp3)–H fluoroalkylation of glycine derivatives with fluorinated peroxy esters

“…As we know, the weak O–O bond with an average energy of ∼35 kcal mol −1 easily generates reactive radical intermediates through thermal homolysis or a SET event. 11 We preferentially attempted to activate the O–O bond of 2a with the thermolysis strategy. By this means, the use of a transition metal catalyst can be avoided, ensuring no metal residue in the final products, which is important for the diverse synthesis of bioactive products and drugs.…”