Et₃B-Induced Radical Addition of N,N-Dichlorosulfonamide to Alkenes and Pyrrolidine Formation via Radical Annulation

Abstract

A highly regioselective radical addition of N,N-dichlorobenzenesulfonamide (dichloramine-B) to 1-alkenes is achieved at -78 degrees C by the use of triethylborane as a radical initiator. The reaction of 1,3-dienes with N,N-dichlorosulfonamide in the presence of Et(3)B regioselectively provides N-chloro-N-allylamide derivatives. N-chloro-N-allylamides thus obtained react with a variety of alkenes to furnish pyrrolidine derivatives in good yields. A radical annulation reaction among N,N-dichlorosulfonamide, 1,3-dienes, and alkenes has been developed.

Copper‐Catalyzed Amination of Arylboronates with N,N‐Dialkylhydroxylamines

“…In addition, a [Ir(OMe)(cod)] 2 /P[3,5-(CF 3 ) 2 C 6 H 3 ] 3 -catalyzed ortho borylation [12] could be followed by the amination to furnish the corresponding 1,2,3-trisubstituted aniline 4 c. These examples demonstrate that the sequential Ir/Cu process could give a rapid and concise approach to anilines having electrondeficient substituents. [15] A stoichiometric reaction of 5 with 2 b in the presence of dppbz gave no detectable amount Scheme 2. This is a significant advantage because the pinacol boronates tend to be less reactive than the parent boronic acids and their successful conversion is not trivial under the conventional Chan-Lam coupling conditions.…”

Radical Addition-Initiated Domino Reactions of Conjugated Oxime Ethers

“…[67][68][69][70][71] In addition, these compounds have not been biologically evaluated in great detail, despite their biological potential. The development of straightforward, flexible, and general synthetic methods for the construction of compounds containing this scaffold from relatively simple substrates is therefore highly desirable.…”

Convergent Assembly of Enantioenriched Tetrahydrobenzofuro[2,3‐b]pyrrole Scaffolds by AgI‐Catalyzed Asymmetric Domino Reaction of Isocyanoacetates

“…Chiral tetrahydrobenzofuro[2, 3-b]pyrroles, especiallyt hose bearing characteristic quaternary carbon stereogenic centers at the ring junctions, are core scaffolds embedded in al arge array of biologically active substances ( Figure 1). [1] However,a ssembly strategiesf or these tricyclics caffolds currently are very limited.E xisting methodss uch as the stepwise C3-arylation/C2oxygenation of indoles, [2] skeletal rearrangement of benzoxazines [3] and chromen-2-ones, [4] cyclization of nitrones, [5] cycloaddition of dichloroketenes with sulfilimines, [6] radical annulation of N-chlorosulfonamides with benzofurans, [7] and also the recently developed radical-initiated cyclativer earrangemento f conjugated aryl oxime ether, [8] always suffer from multiple synthetic steps,u navailabilityo fs tarting materials, and/or lack of enantioselectivity.H ence, the development of novel, efficient, and particularly asymmetrica ccesses from readily available startingm aterials is undoubtedly of significance and deserves investigation.…”