26029-56-1

Upstream product

• 63801-42-3 N-(3-tert-Butyl-1-methylaziridin-1-ylidene)-N-tert-butylamine 
• 27270-94-6 N-(1,3-di-tert-Butylaziridin-2-ylidene)methanamine 
• 6830-83-7 N-methyl-pivalamide 

Downstream Products

• 167149-26-0 cis-N-<2,2-dimethyl-1-(1-propenyloxy)propyl>-N-methylbenzamide 
• 167149-09-9 N-<2,2-dimethyl-1-(2-propenyloxy)propyl>-N-methylbenzamide 

Relevant academic research and scientific papers

Iridium-catalyzed reduction of secondary amides to secondary amines and imines by diethylsilane

Catalytic reduction of secondary amides to imines and secondary amines has been achieved using readily available iridium catalysts such as [Ir(COE) 2Cl]2 with diethylsilane as reductant. The stepwise reduction to secondary amine proceeds through an imine intermediate that can be isolated when only 2 equiv of silane is used. This system requires low catalyst loading and shows high efficiency (up to 1000 turnovers at room temperature with 99% conversion have been attained) and an appreciable level of functional group tolerance.

Synthesis and Thermal Reorganisations of Iminoaziridines. Ab Initioo Calculations of Their Transition States, of Diazatrimethylenemethanes, and Some Cyclic Members of the C2H4N2 Potential-Energy Hypersurface

2-Iminoaziridine 19 and the pairs of isomers 22/23 and 32/33 can be obtained in high yields by base-induced 1,3-dehydrohalogenation of the corresponding α-halo amidines.Regioselectivity of the ring closure reaction of 21 is achieved by treatment with potassium hydride as base in the presence of 18-crown-6 to afford almost exclusively 23.At low temperatures, the cyclisation of 21a under the influence of potassium tert-butoxide occurs diastereoselectively yielding (Z)-22 and (Z)-23 (87:13).Resolution of racemic 21a can be attained by single recrystallisation of the nicely crystallised mandelates of the like configuration, thus providing an efficient route to (R)- and (S)-23 of high enantiomeric purity.Chiroptical data are reported for 21a and 23. - (E)- and (Z)-22 equilibrate faster by more than one order of magnitude than (E)- and (Z)-23 but almost the same preference for the E diastereomer is found in both cases. - Only first-order decomposition into isocyanides 6 and imines is observed on thermolysis of 19, 22, 23, and 32 with activation parameters depending on the substitution pattern.In contrast, the thermal valence isomerisation 35 -> 36 is fast enough to complete with the cycloreversion of 35.Thermal racemisation of (R)-23 does not occur.Quantum-chemical calculations were performed on the parent iminoaziridines (E)- and (Z)-38, 3-amino-2H-azirine (39), the methylenediaziridines cis- and trans-40, and diastereomeric closed-shell and open-shell planar (41) and (open-shell) "mono-orthogonal" diazatrimethylenemethanes 42, 43.Complete geometry optimisations were appropriately performed with the RHF/6-31+G** and the UHF/6-31+G** basis sets.Energies of the closed-shell states were calculated on the RHF, MP2, MP4SDTQ, and CCSD(T) levels, those of open-shell states on the UHF, UMP2, UMP4SDTQ, and CCSD(T)/UHF levels. - (E)-38, being lowest in energy of the parent iminoaziridines (Erel = 0.0), equilibrates with (Z)-38 via an almost linear transition state (Erel = 113.4 kJ mol-1) and decomposes into hydrogen isocyanide and formaldimine in a one-step cheletropic process rel = 179.8 kJ mol-1, CCSD(T)/RHF> with a highly unsymmetrical transition state in which the N1-C2 bond is almost completely broken whereas the C2-C3 bond is still strong.The same is true for the cheletropic decomposition of (Z)-38 the transition state of which (Erel = 168.2 kJ mol-1) is even lower by 11.6 kJ mol-1. - Energy-rich zwitterionic transition states are found with the RHF method among which 1A'-(E,Z)-41 is lowest in energy rel = 203.0 ... - Keywords: Aziridines, 2-imino-, chiral, non-racemic; Amidines, N,N'-dialkyl-2-halo-; 1,3-Dehydrohalogenation, regioselectivity and diastereoselectivity of; E/Z Diastereomerisation; Cycloreversion of isocyanides and imines; Valence isomerisation; Calculations, high-level ab initio, RHF, UHF, MPn, CCSD(T); 2H-Azirine, 3-amino; Diaziridine, 3-methylene; Diazatrimethylenemethanes, diastereomeric, closed-shell and open-shell; Reorganisations, transition states of thermal

Synthesis and Thermolysis of a Chiral, Non-Racemic Iminoaziridine

The 2-halo imidoyl chlorides 7 are obtained from the amide 5 and the 2-halo amides 6 by the action of phosphorus pentachloride and thionyl chloride, respectively.Non-racemic (S)-6a is converted into 7a which is racemic, however.The reaction of Lawesson's reagent with 6a furnishes the diasteromeric 1,3,2-thiazaphospholidine derivatives 15.Treatment of (S)-6a (98percent ee) with methyl triflate affords 2-chloro imidate 8 (95percent ee) which reacts with methanamine in the presence of methanammonium chloride to yield the 2-chloro amidine (S)-9a (90percent ee).The 2-halo imidoyl halides 7a and b react with methanamine to produce the 2-halo amidines 9a and b. - Strong bases, e.g. potassium tert-butoxide or sodium hydride in the presence of catalytic amounts of tert-butyl alcohol, eliminate hydrogen chloride or bromide from the 2-halo amidines 9a and b and (S)-9a to yield mixtures of the 2-iminoaziridines (E)- and (Z)-4, and (E,R)- and (Z,R)-4 (83percent ee), respectively.The 1,3-elimination of hydrogen bromide from 9b is diastereoselective at -30 to -40 deg C 90>.The diastereomers equilibrate at 36 deg C with (kEZ + kZE) = (5.92+/-0.08)*1E-5 s-1 (K = kEZ/kZE = 0.428 +/- 0.013). - The thermolysis of (E)- and (Z)-4 in 6>benzene solution yields the imine 16 and methyl isocyanide (17).The decomposition follows the first-order rate law.The following Arrhenius and Eyring parameters are calculated from five rate constants obtained in the temperature range of 70-110 deg C.Ea = (115.2 +/-0.4) kJmol-1, lgA = (12.06 +/- 0.28), ΔH(excit.) = (112.1 +/- 0.4) kJmol-1, ΔS(excit.) = (-23.9 +/- 0.7) JK-1 mol-1, ΔG(excit.) 373K = 121 kJmol-1.The enantiomeric excess of the surviving fraction of (E,R)- and (Z,R)-4 is unchanged after two half-lives at 80 deg C. - Key Words: Aziridines, 2-imino-, chiral, non-racemic / Imidoyl halides, 2-halo / Imidates, 2-chloro / 1,3,2-Thiazaphospholidines / Amidines, 2-halo / 1,3-Elimination, inversion of configuration in / E/Z Diastereomerization / Cycloreversion, kinetics of thermal