Formation of Quaternary Stereogenic Centers by Copper-Catalyzed Asymmetric Conjugate Addition Reactions of Alkenylaluminums to Trisubstituted Enones
作者:Daniel Müller、Alexandre Alexakis
DOI:10.1002/chem.201302856
日期:2013.11.4
undergo asymmetric copper‐catalyzedconjugateaddition (ACA) to β‐substituted enones allowing the formation of stereogenic all‐carbon quaternary centers. Phosphinamine–copper complexes proved to be particularly active and selective compared with phosphoramidite ligands. After extensive optimization, high enantioselectivities (up to 96 % ee) were obtained for the addition of alkenylalanes to β‐substituted
Asymmetric Palladium-Catalyzed Alkene Carboamination Reactions for the Synthesis of Cyclic Sulfamides
作者:Zachary J. Garlets、Kaia R. Parenti、John P. Wolfe
DOI:10.1002/chem.201600887
日期:2016.4.18
The synthesis of cyclic sulfamides by enantioselective Pd‐catalyzed alkene carboamination reactions between N‐allylsulfamides and aryl or alkenyl bromides is described. High levels of asymmetric induction (up to 95:5 e.r.) are achieved using a catalyst composed of [Pd2(dba)3] and (S)‐Siphos‐PE. Deuterium‐labelling studies indicate the reactions proceed through syn‐aminopalladation of the alkene and
Five-membered metallacycloallene compounds that are 2,5-disubstituted 1-zirconacyclopenta-2,3-dienes were prepared from (E)-1,4-bis(trialkylsilyl)but-1-en-3-ynes in good yields. The structures of these compounds were determined by X-ray diffraction study. Contrary to our previous study on 2,4-disubstituted 1-zirconacyclopenta-2,3-dienes, which gave alkynyl alcohols by the reaction with ketones after
Preparation of 1-substituted-3,4-dihydronaphthalene-2-carboxaldehyde N,N-dimethylhydrazones by palladium(0) coupling, and their electrocyclic ring closure
作者:Thomas L. Gilchrist、Maureen A.M. Healy
DOI:10.1016/s0040-4020(01)86333-x
日期:1993.3
involving halogen-metal exchange and palladium(0) catalysed cross coupling, into N,N-dimethylhydrazones of 1-aryl- and 1-vinyl-3,4-dihydronaphthalene-2- carboxaldehydes. The N,N-dimethylhydrazone 10 of the aldehyde 2 undergoes efficient bromine-lithium exchange with butyllithium, as does 2-bromobenzaldehyde N,N-dimethylhydrazone 17. The dimethylhydrazones of 1-vinyl-3,4-dihydronaphthalene-2-carboxaldehydes
Synthesis of Enantioenriched Allylic Silanes via Nickel-Catalyzed Reductive Cross-Coupling
作者:Julie L. Hofstra、Alan H. Cherney、Ciara M. Ordner、Sarah E. Reisman
DOI:10.1021/jacs.7b11707
日期:2018.1.10
asymmetric Ni-catalyzed reductive cross-coupling has been developed to prepare enantioenriched allylic silanes. This enantioselective reductive alkenylation proceeds under mild conditions and exhibits good functional group tolerance. The chiral allylic silanes prepared here undergo a variety of stereospecific transformations, including intramolecular Hosomi-Sakurai reactions, to set vicinal stereogenic centers
已开发出不对称 Ni 催化的还原交叉偶联来制备对映体富集的烯丙基硅烷。这种对映选择性还原烯基化在温和条件下进行,并表现出良好的官能团耐受性。这里制备的手性烯丙基硅烷经过各种立体定向转化,包括分子内细美-樱井反应,以设置具有优异手性转移的邻位立体中心。