39739-50-9Relevant academic research and scientific papers
Atropisomerization in N-aryl-2(1H)-pyrimidin-(thi)ones: A ring-opening/rotation/ring-closure process in place of a classical rotation around the pivot bond
Najahi, Ennaji,Vanthuyne, Nicolas,Nepveu, Francoise,Jean, Marion,Alkorta, Ibon,Elguero, Jose,Roussel, Christian
, p. 12577 - 12584 (2013)
Uncatalyzed racemization processes in atropisomeric diphenyl-like frameworks are classically described as the result of the rotation around the pivotal single bond linking two planar frameworks. Severe constraints leading to more or less distorted transit
Transition-metal-free approach to 4-ethynylpyrimidines via alkenynones
Golubev, Pavel R.,Pankova, Alena S.,Kuznetsov, Mikhail A.
, p. 3614 - 3621 (2014/06/23)
A practical approach to the synthesis of 4-ethynylpyrimidines by the condensation of arylamidines with 2-aryl-1-ethoxy-5-(trimethylsilyl)pent-1-en-4- yn-3-ones has been developed. As these latter ketones are easily accessible from bis(trimethylsilyl)acetylene and arylacetyl chlorides, the regioselective condensation reported herein provides a facile access to both TMS-protected and unprotected 4-ethynylpyrimidines in yields of up to 85%. Copyright
Efficient synthesis of α-tertiary α-silylamines from aryl sulfonylimidates via one-pot, sequential C-Si/C-C bond formations
Han, Xiao-Jun,Yao, Ming,Lu, Chong-Dao
supporting information; experimental part, p. 2906 - 2909 (2012/07/14)
An efficient and flexible route for the synthesis of α-tertiary (α,α-dibranched) α-silylamines via sequential reactions of sulfonylimidates using readily available phenyldimethylsilyllithium and Grignard reagents is described. The procedure allows successive formation of C-Si/C-C bonds in a single flask.
Chichibabin-type condensation of cyclic ketones with 3-R-1,2,4-triazin-5(4 H)-ones
Egorov, Ilya N.,Tseitler, Tatyana A.,Kovalev, Igor S.,Slepukhin, Pavel A.,Rusinov, Vladimir L.,Chupakhin, Oleg N.
experimental part, p. 6007 - 6013 (2012/10/08)
Reactions between substituted 1,2,4-triazines and ketones were investigated. General procedures for one-pot synthesis of hydrogenated derivatives of such polycyclic systems as benzo[c][1,2,4]triazino[1,6-a][2] azecine, [1,2,4]triazino[1,6-f]phenantridine, and dicyclopenta[b,d]pyrido[1,2-f] [1,2,4]triazine are described.
18O exchange accompanying the basic hydrolysis of primary, secondary, and tertiary toluamides. 2. The importance of amine leaving abilities from the anionic tetrahedral intermediates
Slebocka-Tilk,Bennet,Keillor,Brown,Guthrie, J. Peter,Jodhan
, p. 8507 - 8514 (2007/10/02)
A series of primary, secondary, and tertiary toluamides (CH3(C6H4)C=ONR1R2) was studied with respect to their hydrolysis and C=O, 18O exchange rate constants in basic media at 100 °C. For the primary amides (R1 = R2 = H) the kex/khyd ratio is 3.7 ± 0.2 and is independent of [OH-]. For the secondary toluamides R1 = H, R2 = Et, iPr, or tBu, the kex/khyd ratio is constant at 0.4-0.75, despite the fact that khyd drops from 1.0 to 0.22 to 0.02 in passing through the series. The tertiary toluamides R1 = R2 = CH3, R1, R2 = (CH2)4 have kex/khyd = 0.01-0.02 in H2O, and that ratio increases somewhat in D2O. Analysis of the energetics of the various possible intermediates, and their barriers for interconversion and breakdown, produces a mechanism consistent with presently known experimental data. The reaction proceeds stepwise via the addition of OH- to produce an anionic intermediate (T-). Breakdown of T- to product involves a water-mediated proton switch to give an anionic zwitterion followed by rate-limiting C-N cleavage. By study of the partitioning of unsymmetrical amidines in base at 100 °C, an order of leaving ability from an anionic intermediate is established where R2NH (130-180) > RNH2 (15-20) > NH3 (1.0). These data account for the observed kex/khyd ratios for the corresponding amides and indicate that amine leaving ability determines whether a given amide will exhibit significant 18O exchange.
