4460-46-2Relevant academic research and scientific papers
Carbon Atom Insertion into Pyrroles and Indoles Promoted by Chlorodiazirines
Dherange, Balu D.,Kelly, Patrick Q.,Levin, Mark D.,Liles, Jordan P.,Sigman, Matthew S.
supporting information, p. 11337 - 11344 (2021/08/16)
Herein, we report a reaction that selectively generates 3-arylpyridine and quinoline motifs by inserting aryl carbynyl cation equivalents into pyrrole and indole cores, respectively. By employing α-chlorodiazirines as thermal precursors to the corresponding chlorocarbenes, the traditional haloform-based protocol central to the parent Ciamician-Dennstedt rearrangement can be modified to directly afford 3-(hetero)arylpyridines and quinolines. Chlorodiazirines are conveniently prepared in a single step by oxidation of commercially available amidinium salts. Selectivity as a function of pyrrole substitution pattern was examined, and a predictive model based on steric effects is put forward, with DFT calculations supporting a selectivity-determining cyclopropanation step. Computations surprisingly indicate that the stereochemistry of cyclopropanation is of little consequence to the subsequent electrocyclic ring opening that forges the pyridine core, due to a compensatory homoaromatic stabilization that counterbalances orbital-controlled torquoselectivity effects. The utility of this skeletal transform is further demonstrated through the preparation of quinolinophanes and the skeletal editing of pharmaceutically relevant pyrroles.
Experimental and Computational Mechanistic Investigation of Chlorocarbene Additions to Bridgehead Carbene-Anti-Bredt Systems: Noradamantylcarbene-Adamantene and Adamantylcarbene-Homoadamantene
Hare, Stephanie R.,Orman, Marina,Dewan, Faizunnahar,Dalchand, Elizabeth,Buzard, Camilla,Ahmed, Sadia,Tolentino, Julia C.,Sethi, Ulweena,Terlizzi, Kelly,Houferak, Camille,Stein, Aliza M.,Stedronsky, Alexandra,Thamattoor, Dasan M.,Tantillo, Dean J.,Merrer, Dina C.
, p. 5049 - 5065 (2015/06/02)
Cophotolysis of noradamantyldiazirine with the phenanthride precursor of dichlorocarbene or phenylchlorodiazirine in pentane at room temperature produces noradamantylethylenes in 11% yield with slight diastereoselectivity. Cophotolysis of adamantyldiazirine with phenylchlorodiazirine in pentane at room temperature generates adamantylethylenes in 6% yield with no diastereoselectivity. 1H NMR showed the reaction of noradamantyldiazirine + phenylchlorodiazirine to be independent of solvent, and the rate of noradamantyldiazirine consumption correlated with the rate of ethylene formation. Laser flash photolysis showed that reaction of phenylchlorocarbene + adamantene was independent of adamantene concentration. The reaction of phenylchlorocarbene + homoadamantene produces the ethylene products with k = 9.6 × 105 M-1 s-1. Calculations at the UB3LYP/6-31+G(d,p) and UM062X/6-31+G(d,p)//UB3LYP/6-31+G(d,p) levels show the formation of exocyclic ethylenes to proceed (a) on the singlet surface via stepwise addition of phenylchlorocarbene (PhCCl) to bridgehead alkenes adamantene and homoadamantene, respectively, producing an intermediate singlet diradical in each case, or (b) via addition of PhCCl to the diazo analogues of noradamantyl- and adamantyldiazirine. Preliminary direct dynamics calculations on adamantene + PhCCl show a high degree of recrossing (68%), indicative of a flat transition state surface. Overall, 9% of the total trajectories formed noradamantylethylene product, each proceeding via the computed singlet diradical.
Hammett analysis of a family of carbene-carbene complex equilibria
Wang, Lei,Moss, Robert A.,Thompson, Jack,Krogh-Jespersen, Karsten
body text, p. 1198 - 1201 (2011/04/27)
p-X-substituted phenylchlorocarbenes (X = NO2, CF3, Cl, H, Me, and MeO) form π-type complexes with trimethoxybenzene in pentane. The carbenes and complexes are in equilibrium, and logarithms of the measured equilibrium constants are well correlated by Hammett σp constants with ρ = 2.48. The carbene complexes are characterized by UV-vis spectroscopy, and computational analysis is afforded by DFT calculations.(Figure Presented)
Reactivity of 1-chloro-3-phenyldiazirines
Martinu, Tomas,Dailey, William P.
, p. 5012 - 5015 (2007/10/03)
p-Substituted 1-chloro-3-phenyldiazirines (5), the putative intermediates of the reaction of N,N,N′-trichlorobenzamidines (10) with excess of bromide ions, react further to afford mixtures of 3-bromo- (4) and 3-chloro-3-phenyldiazirines (6). The 6:4 ratio
Inter- and innermolecular reactions of chloro(phenyl)carbene
Rosenberg, Murray G.,Brinker, Udo H.
, p. 4819 - 4832 (2007/10/03)
Supramolecular photolyses of 3-chloro-3-phenyl-3H-diazirine (8) were performed within cyclodextrin (CyD) hosts to determine whether these toroidal inclusion compounds could alter the reactivity of the ensuing carbene reaction intermediate, chloro(phenyl)carbene (9). Remarkably, no intramolecular products stemming from carbene 9 could be detected. Instead, modified CyDs were formed via so-called innermolecular reactions. Hence, diazirine 8 was photolyzed in various conventional solvents to gauge the intermolecular reactivity of carbene 9. Relevant results were used to rationalize the CyD innermolecular reaction products.
A Willgerodt-Kindler Type Selenation of Dihalomethane Derivatives, Chloroform, and Sodium Trichloroacetate by Treating with a Base, Elemental Selenium, and an Amine
Shimada, Kazuaki,Yamaguchi, Minoru,Sasaki, Tohru,Ohnishi, Kenji,Takikawa, Yuji
, p. 2235 - 2242 (2007/10/03)
Treatment of dihalomethane derivatives, chloroform, or sodium trichloroacetate with elemental selenium in the presence of NaH and an excess amount of an amine gave the corresponding selenoamides, selenoureas, and bis(selenocarbamoyl) triselenides in modest yields. These products were afforded from reactive intermediates related to "selenocarbonyl halides" and "selenophosgenoids" generated by the reaction of dichloromethanide ions and trichloromethanide ion with N-alkylated aminopolyselenide species (R2N-(Se)n-).
1,2,4,6-CYCLOHEPTATETRAENE: THE KEY INTERMEDIATE IN ARYLCARBENE INTERCONVERSIONS AND RELATED C7H6 REARRANGEMENTS
McMahon, Robert J.,Abelt, Christopher J.,Chapman, Orville L.,Johnson, Jeffery W.,Kreil, Curits L.,et al.
, p. 2456 - 2469 (2007/10/02)
Thermolysis or photolysis of phenyldiazomethane (2) produces phenylmethylene (3), which ring-expands to give 1,2,4,6-cycloheptatetraene (6).Spectroscopic and chemical evidence rule out bicyclo(4.1.0)hepta-2,4,6-triene (4), cycloheptatrienylidene (5), and bicyclo(3.2.0)hepta-1,3,6-triene (11) intermediates.The strained allene in cycloheptatetraene (6) exhibits infrared absorption at 1824 and 1816 cm-1.Deuterium substitution produces the expected 10-cm-1 shift in the allene absorption.Fluorine or chlorine substitution substantially enhances the allene absorption intensity.Deuterium labeling studies reveal that the intramolecular chemistry of cycloheptatetraene (6) involves reversible thermal or photochemical equilibriation with phenylmethylene (3).The intermolecular chemistry of 6 involves dimerization.At temperatures as low as 10 K, 6 forms a labile (2+2) dimer,7, which undergoes thermally allowed, electrocyclic ring opening to give heptafulvalene (8) upon warming to room temperature.The rearrangements of 7-acetoxynorbornadiene (9), 2-diazobicyclo(3.2.0)hepta-3,6-diene (31), and 8-diazobicyclo(2.2.2)octa-2,5-dien-7-one (33) all involve cycloheptatetraene (6) intermediates.
ABSOLUTE RATE CONSTANTS FOR THE ADDITIONS OF HALOPHENYLCARBENES TO ALKENES; A REACTIVITY-SELECTIVITY RELATION
Cox, D. Phillip,Gould, Ian R.,Hacker, Nigel P.,Moss, Robert A.,Turro, Nicholas J.
, p. 5313 - 5316 (2007/10/02)
The absolute rate constants determined for the additions of FCPh, ClCPh, and BrCPh to Me2C=CMe2, Me2C=CHMe, trans-MeCH=CHEt, and n-BuCH=CH2, appear to follow a reactivity/selectivity pattern of the "normal" (inverse) type.
3-Aryl-3-chlor-1,2-diaziridine als isolierbare Zwischenprodukte bei der Darstellung von 3-Aryl-3-chlor-3H-1,2-diazirinen
Berneth, Horst,Huenig, Siegfried
, p. 2040 - 2042 (2007/10/02)
The formation of 3-aryl-3-chloro-3H-1,2-diazirines 3 from arylamidines 1 with sodium hypochlorite passes through intermediate 3-aryl-3-chloro-1,2-diaziridines 2, which are isolable at low temperature.The direct path 1 -> 3 so far suggested therefore becom
