Gas-phase pyrolytic reactions of N-ethyl, N-isopropyl, and N-t-butyl substituted 2-aminopyrazine and 2-aminopyrimidine

An (Aminopyrimidinato)titanium Catalyst for the Hydroamination of Alkynes and Alkenes

“…However, initial hydroamination reactions of 1-phenylpropyne (3) with p-toluidine (4) revealed that complex 2 is a competent catalyst for the intermolecular hydroamination of alkynes (Table 1). [8] Figure 1. Particularly important is the fact that no formation of the Markovnikov regioisomer 5b could be observed by GC analysis.…”

“…Aminopyrimidine 1 is easily accessible in one step from commercially available and inexpensive 2-chloropyrimidine and tert-butylamine by nucleophilic aromatic substitution. [8] Treatment of [Ti(NMe 2 ) 4 ] with two equivalents of ligand precursor 1 at room temperature in diethyl ether resulted in the clean formation of aminopyrimidinato complex 2 in excellent yield (Scheme 1). The obtained solid material could be recrystallized from hexanes to give red crystals that were suitable for X-ray crystallographic analysis ( Figure 1).…”

“…Synthesis of bis[2-(tert-butylamino)pyrimidine]bis(dimethylamino)titanium (2). [8] Figure 1. X-ray crystal structure of complex 2.…”

“…[8] Prior to use, all alkynes, amines and aminoalkenes were purified by Kugelrohr distillation and degassed. Complex [Ti(NMe 2 ) 4 ], tert-butylamine, 2chloropyrimidine and toluene (toluene extra dry with molecular sieves) were purchased from Acros Organics.…”

Chemistry of 2-Arylhydrazonals: Utility of Substituted 2-Arylhydrazono-3-Oxoalkanals as Precursors for 3-Oxoalkanonitriles, 3-Aminoisoxazole and 1,2,3- and 1,2,4-Triazoles

“…Similar assumption has been made to account for the formation of such TS in analogous thermal gas-phase processes involving halogen acid elimination reactions (Scheme 3). 23 In an attempt to present a more complete pattern of transformation of the oxime series, we have also studied the effect of substituents on the a-aryl moiety. It was initially envisaged that the cyclisation reaction of compound 7d to yield the b-ketonitrile derivative 13d would be enhanced by the (+ I) effect of the para methyl group.…”