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A dataset of highly accurate homolytic NBr bond dissociation energies obtained by Means of W2 theory

“…Examples of reactions involving initial NABr bond homolysis include: (i) The well-known Hofmann-L€ offler-Freytag reaction, in which N-bromoalkylammonium derivatives containing a dhydrogen may be cyclized to form pyrrolidines, [13] (ii) The reaction between N-bromophthalimide and alkynes, in which the products are alkenes containing a bromine atom and imide moiety vicinal to each other, [14] (iii) The photochemical bromination reactions of alkanes affording bromoalkanes, [15] (vi) The degradation of extracellular matrix and its components via the formation of glycosaminoglycan-derived nitrogen-centered radicals, [5] and (v) The oxidation of alcohols to aldehydes or ketones with phenyl N-bromoketimine. [16] Given that homolytic NABr bond cleavage constitutes the initiation step for numerous reactions involving N-brominated species, knowledge of the strength of NABr bonds is of the utmost importance.…”

Intermolecular Radical Additions to Alkynes: Cascade‐Type Radical Cyclizations

“…, which were generated through photolysis of N-bromophthalimide, with cyclodecyne (52) leads to formation of small amounts of unsaturated bicyclic compounds 96 and 97 among other products (not shown). 45 This sequence is believed to proceed via initial addition of Im . to the C:C triple bond, which initiates a sequence of transannular HAT (98 !…”

Thiophenol‐Mediated 1,5‐Hydrogen Atom Abstraction: Easy Access to Mono‐ and Bicyclic Compounds

“…[48] Substituted 5-cycloalkylpent-1-yne derivatives 16a -16d were investigated next according to Scheme 13 [Eq. (11)]. The non-substituted precursor 16a affords none of the desired spirocyclic derivative 17a.…”

“…[2,6] However, the practicability of this process is hampered by the use of tin derivatives and by the formation of uncyclized product via direct reduction of the intermediate alkenyl radical. Radical addition to terminal or disubstituted alkynes offers an attractive alternative for the generation of alkenyl radicals that undergo 1,5-translocation to alkyl radicals and 5-exo-trig cyclization (related reactions involving the formation of heterocycles via transient silyl, [7,8] alkoxyl [9,10] and imidyl [11] radicals are also reported). Inter-and intramolecular additions of carbon-centered radicals are utilized to initiate such cascade processes.…”