Intermolecular Acetoxyaminoalkylation of α-Diazo Amides with (Diacetoxyiodo)benzene and Amines

Abstract

Multicomponent reactions of diazo compounds have attracted much attention in recent years. Such transformations are generally conducted by applying transition metal catalysis and involve the corresponding metal carbenes as key intermediates. In this letter, a metal-free threecomponent intermolecular acetoxyaminoalkylation of αdiazo amides with tertiary aryl amines and (diacetoxyiodo)benzene is presented.

Reactions between Diazo Compounds and Hypervalent Iodine(III) Reagents

“…The success of this strategy depended on the appropriate use of the carboxylate variant of ethynylbenziodoxol(on)e (EBX) reagents 34 as a nucleophile, and the alkyne as an electrophile. Compared with the above‐mentioned three‐component difunctionalizations (Schemes –), the EBX reagents 34 acted as both a tethered nucleophile and electrophile in this particular case. Meanwhile, the complete incorporation of the hypervalent iodine(III) reagent as a reaction partner without the formation of stoichiometric iodoarene byproducts led to higher atom economy and the generation of N 2 as the only waste product.…”

“…In 2018, Studer and co‐workers expanded the scope of three‐component difunctionalizations of diazo compounds to acetoxyaminoalkylation by combining α‐diazo amides 28 with (diacetoxyiodo)benzene (PIDA, 30 ) and amines 29 (Scheme ) . Without the involvement of metal carbenes as key intermediates, iminium ion G is formed after sequential single electron transfer (SET) oxidation processes by the iodine(III) reagent 30 , which is followed by the combination with α‐diazo compound 28 .…”

Three‐Component Reaction for the Synthesis of Highly Functionalized Propargyl Ethers

“…In the absence of a metal‐catalyst, Murphy and co‐workers have first reported dihalogenation reactions . More recent examples involve acetoxyaminoalkylation and azidoaminoalkylation . The first transformations involving metal carbene intermediates were reported independently by our group and Szabo and co‐workers .…”

C1‐Functionalization of 1,2,3,4‐Tetrahydroisoquinolines (THIQs)

“…In 2018, Studer et al synthesized derivatives of C1-substituted THIQ 56 in good to high yields (86-95%) in methanol at room temperature. [26] These compounds 56 were obtained from the three-component intermolecular acetoxyaminoalkylation of N-arylated THIQs 46 with (diacetoxyiodo)-benzene (PIDA) 52 and 2-diazo-N,N-dimethylacetamide 53 under reaction conditions (Scheme 9). Based on the proposed mechanism, this process is started by in situ generation of iminium ions 54 and acetate anion as the counterion via oxidation of N-arylated THIQs 46 by PIDA 52.…”