A detailed investigation of the aza-Prins reaction
作者:Adrian P. Dobbs、Sebastien J. J. Guesné、Robert J. Parker、John Skidmore、Richard A. Stephenson、Mike B. Hursthouse
DOI:10.1039/b915797b
日期:——
The development of a Lewis acid-promoted aza-Prins reaction to form piperidines and pyrrolidines is described. Indium trichloride has been found to be a highly successful and mild Lewis acid for promoting this reaction. A thorough mechanistic investigation is described, including the factors that influence the formation of the 5- or 6-membered ring product(s).
Small-Ring Compounds. XLIII. Formolysis of Substituted Allylcarbinyl Tosylates<sup>1</sup>
作者:Kenneth L. Servis、John D. Roberts
DOI:10.1021/ja01084a031
日期:1965.3
function of methyl substitution in 3- and 4-positions and phenyl substitution at the 4-position in the formolysis of allylcarbinyl tosylate. The largest factor, 4.5 x 10^3, was observed for (γ,γ dimethylallyl)carbinyl tosylate. The nature of the solvolytic transitionstate is discussed; the results are shown to be inconsistent with formation of classical carbonium ion intermediates.
Radical–Radical Cyclization Cascades of Barbiturates Triggered by Electron-Transfer Reduction of Amide-Type Carbonyls
作者:Huan-Ming Huang、David J. Procter
DOI:10.1021/jacs.6b04086
日期:2016.6.22
radical-radical cyclizationcascades. An alternative fragmentation-radical cyclization sequence of related substrates allows access to bicyclic uracil derivatives. The radical-radical cyclizationprocess constitutes the first example of a radical cascade involving ET reduction of the amide carbonyl. Products of the cascade can be readily manipulated to give highly unusual and medicinally relevant bi-
自由基-自由基环化级联由 SmI2-H2O 向酰胺型羰基的单电子转移触发,一步将简单的非手性巴比妥酸盐转化为含半胺或烯胺的三环支架,其中含有多达五个连续的立体中心(包括四元立体中心)。此外,我们描述了 LiBr 对最具挑战性的自由基 - 自由基环化级联的惊人有益影响。相关底物的另一种断裂-自由基环化序列允许获得双环尿嘧啶衍生物。自由基-自由基环化过程构成了涉及酰胺羰基 ET 还原的自由基级联的第一个例子。级联产物可以很容易地得到非常不寻常和医学上相关的双环和三环巴比妥酸盐。
Unexpected Formation of a trans-syn-Fused Linear Triquinane from a Trimethylenemethane (TMM)-Diyl-Mediated [2+3] Cycloaddition Reaction.
作者:Won-Yeob Kim、Byung Gyu Kim、Taek Kang、Hee-Yoon Lee
DOI:10.1002/asia.201100251
日期:2011.8.1
trans‐Fused triquinane: Intramolecular‐trimethylenemethane‐mediated [2+3] cycloadditionreaction of a highly congested substrate proceeded stepwise to produce highly strained triquinane structures along with tricyclo[5.3.1.02, 6]undecanes.
Regioselective Epoxidations by Cytochrome P450 3A4 Using a Theobromine Chemical Auxiliary to Predictably Produce N-Protected β- or γ-Amino Epoxides
作者:Vanja Polic、Kin Jack Cheong、Fabien Hammerer、Karine Auclair
DOI:10.1002/adsc.201700637
日期:2017.11.23
N-Protected β- and γ-aminoepoxides are useful chiral synthons. We report here that the enzyme cytochrome P450 3A4 can catalyze the formation of such compounds in a regio- and stereoselective manner, even in the presence of multiple double bonds or aromatic substituents. To this end, the theobromine chemical auxiliary is used not only to control the selectivity of the enzyme, but also as a masked amine