A Radical Bidirectional Fragment Coupling Route to Unsymmetrical Ketones
作者:Lucile Anthore-Dalion、Qiang Liu、Samir Z. Zard
DOI:10.1021/jacs.6b05344
日期:2016.7.13
A powerful strategy for the regioselective bidirectional synthesis of unsymmetrically substituted ketones is described, relying on the fact that the exchange of a xanthate is much faster than the radical addition to an unactivated alkene. The use of an alkene as the formal "alkylating" agent associated with the tolerance for numerous functional groups and the mildness of the experimental conditions
Formation of α-iminoketones and α-diimines versus Favorskii rearrangement products from the reaction of α,α′-dibromoketones and primary amines
作者:Norbert De Kimpe、Luc D'Hondt、Luc Mones
DOI:10.1016/s0040-4020(01)92258-6
日期:1992.4
reaction of aliphatic acyclic α,α′-dibromoketones with primary amines gave rise to α-iminoketones and α-diimines. Both reaction products could be selectively obtained under appropriate reaction conditions. Sterically hindered α,α-dibromoketones did not react with primary amines, although, under forcing conditions the Favorskii rearrangement could be induced. In aqueous methanol, α,α′-dibromoketones reacted
Inhibitors of Thermus thermophilus Isopropylmalate Dehydrogenase
作者:Michael C. Pirrung、Hyunsoo Han、Richard T. Ludwig
DOI:10.1021/jo00088a026
日期:1994.5
In an attempt to use mechanism-based design for the discovery of inhibitors of the isopropylmalate dehydrogenase from T. thermophilus, we have prepared and studied a number of potential mimics for an intermediate in the oxidative decarboxylation of isopropyl malate, the enol or enolate of alpha-ketoisocaproate. Because hydroxamate and dicarboxylate enolate mimics are strong, uncompetitive inhibitors of the enzyme and vinyl fluoride enol mimics are weak, competitive inhibitors, it is suggested that the reaction involves the enolate. The uncompetitive inhibition by a number of anionic compounds suggests, in combination with previous studies in other laboratories, that they mimic the enolate product of the decarboxylation. An explanation for the potency of the inhibition of IMDH by these compounds is proposed based on the electrostatic interaction of product and cofactor.
Pirrung Michael C., Han Hyunsoc, Ludwig Richard T., J. Org. Chem., 59 (1994) N 9, S 2430-2436
作者:Pirrung Michael C., Han Hyunsoc, Ludwig Richard T.
DOI:——
日期:——
Remote control of stereogenicity transfer by ring-generated anisotropic orbital overlap. Stereochemistry of hydrogen shift in the intramolecular reverse ene reaction of a cis-2-alkyl-1-alkenylcyclopropane
作者:Patti A. Parziale、Jerome A. Berson
DOI:10.1021/ja00012a032
日期:1991.6
Pyrolysis of 5 gave only 2-methyl-octa-2(Z),5(Z)-diene-1-d 3 -7(S)-d, with high stereospecificity at each of the three sites of sterogenicity. This result is the one predicted if the reaction is controlled by optimal overlap of the reacting C―H and π bond orbitals with the C s symmetric component of the degenerate 3E' highest occupied orbital of the cyclopropane ring
顺-2-(2-丙基)-1 (E)-丙烯基环丙烷在气相中在接近 230°C 的温度下发生热重排,活化参数为 E a =35.5±0.6 kcal/mol 和 log A = 12.05± 0.5 (A, s -1 )。合成了旋光同位素双标记类似物(cis-2(S)-(2(S)-propyl-1-d 3 )-1(S)-(1(E)-propenyl-2-d)cyclopropane 5)在 12 个步骤中从双环戊二烯中分离出来。5 的热解仅得到 2-methyl-octa-2(Z),5(Z)-diene-1-d 3 -7(S)-d,在三个位点中的每一个都具有高立体特异性如果反应受反应的 C-H 和 π 键轨道与环丙烷环的简并 3E' 最高占据轨道的 C s 对称分量的最佳重叠控制,则该结果是预测的结果