General Zinc-Catalyzed Conia-Ene Reactions of 1,3-Dicarbonyl Compounds with Alkynes Including the Classically Challenging Substrates under Neat Conditions
作者:Chen-Liang Deng、Ren-Jie Song、Yi-Lin Liu、Jin-Heng Li
DOI:10.1002/adsc.200900588
日期:2009.12
products has been developed by zinc-catalyzed intramolecular Conia-enereactions of 1,3-dicarbonylcompounds with alkynes. This new route allows a wide range of dicarbonyl compounds, including the classicallychallenging 1,3-diesters and N,N′-disubstituted 1,3-keto amides, to be used for the Conia-enereaction with inexpensive zinc chloride (ZnCl2) underneatconditions.
Decarboxylative Claisen Rearrangement Reactions of Allylic Tosylmalonate Esters
作者:Donald Craig、Fabienne Grellepois
DOI:10.1021/ol047577w
日期:2005.2.1
[reaction: see text] Two different combinations of silylating agent and base are used for one-pot [3,3]-sigmatropic rearrangement-decarboxylation reactions of tosylmalonic mono(allylic) esters under mild conditions, providing the products of formal regiospecific allylation of methyl tosylacetate at the more substituted allylic terminus.
Enantioselective 1,3-Dipolar Cycloaddition of Azomethine Imines with Propioloylpyrazoles Induced by Chiral π–Cation Catalysts
作者:Masahiro Hori、Akira Sakakura、Kazuaki Ishihara
DOI:10.1021/ja508441t
日期:2014.9.24
We developed 1,3-dipolarcycloadditions of azomethine imines with propioloylpyrazoles catalyzed by a chiral copper(II) complex of 3-(2-naphthyl)-l-alanine amide. The asymmetric environment created by intramolecular π-cation interaction and the N-alkyl group of the chiral ligand gives the corresponding adducts in high yields with excellent enantioselectivity. This is the first successful method for
我们开发了由 3-(2-萘基)-l-丙氨酸酰胺的手性铜 (II) 配合物催化的偶氮甲碱亚胺与丙炔吡唑的 1,3-偶极环加成反应。由分子内 π-阳离子相互作用和手性配体的 N-烷基产生的不对称环境以高产率提供了相应的加合物,并具有出色的对映选择性。这是第一个成功的催化对映选择性 1,3-偶极环加成反应的偶氮甲亚胺与内部炔烃衍生物的方法,得到完全取代的吡唑啉。
Mn(III)-mediated radical lactonisation of allylic esters of acetoacetic and malonic acids
Mn(OAc)3 oxidises allyl acetoacetate and allyl malonate to 3-oxa bicyclo (3.1.0) 2-hexanone derivatives whereas under similar experimental conditions cinnamyl and crotyl esters lead to monocyclic γ-lactones derivatives and bis-lactones.
After 50 years of persistence the 12‐membered cyclic skeleton of bottromycin A2 (3) has been confirmed by NMR experiments (HMBC), and the configurations of two tLeu residues have been estimated by conformation analysis and NMR experiments. Furthermore, the key step in the synthesis of 3 involves the mercury‐mediated formation of the amidine of thioamide 1 and amine 2.