Trialkyl Methanetricarboxylate as Dialkyl Malonate Surrogate in Copper-Catalyzed Enantioselective Propargylic Substitution
摘要:
The first copper-catalyzed enantioselective propargylation of trialkyl methantricarboxylate with propargylic alcohol derivatives was developed. The tricarboxylate unit in the obtained adducts could be easily transformed into a malonate moiety by treating with in situ generated NaOEt in excellent yield without racemization.
β-hydroxyphosphonate analogues is described. The use of a nucleoside β-ketophosphonate as the key intermediate allowed both the (R) and (S) isomers of β-hydroxyphosphonate analogues in the pyrimidineseries to be accessed. Such derivatives may be considered as stable mimics of 5
描述了获得核苷 β-羟基膦酸酯类似物的简明途径。使用核苷 β-酮膦酸酯作为关键中间体允许获得嘧啶系列中 β-羟基膦酸酯类似物的 (R) 和 (S) 异构体。这样的衍生物可以被认为是 5
Gold-catalyzed reactions of propargylic esters with vinylazides for the synthesis of Z- or E-configured buta-1,3-dien-2-yl esters
作者:Sachin Bhausaheb Wagh、Rai-Shung Liu
DOI:10.1039/c5cc05945c
日期:——
Gold-catalyzed synthesis of buta-1,3-dien-2-yl esters by the reaction of propargyl esters with vinylazides is described; the reaction mechanism is postulated to involve a vinyl attack of vinylazides at alkenyl gold carbenes.
Gold(I)-Catalyzed Reactions of Propargyl Esters with Vinyl Derivatives
作者:Christian A. Sperger、Jørn E. Tungen、Anne Fiksdahl
DOI:10.1002/ejoc.201100291
日期:2011.7
A gold-catalyzed olefin cyclopropanation reaction of propargyl esters with vinylester or vinyl sulfonamide derivatives was investigated for the synthesis of highly substituted cyclopropane derivatives in good diastereoselectivity. By varying the vinyl species, trans-cyclopentenyl esters were selectively formed by a formal [3+2] cycloaddition.
Synthesis of α-Acyloxyketone Derivatives <i>via</i> the Platinum-Catalyzed Migration of Propargylic Esters
作者:Chihiro Tsukano、Sho Yamamoto、Yoshiji Takemoto
DOI:10.1248/cpb.c15-00417
日期:——
The synthesis of α-acyloxyketones via the migration of a propargylic ester followed by the intramolecular nucleophilic addition of the resulting allene was achieved using a cationic platinum catalyst. The optimized conditions for this transformation were determined to be 3 mol% of Pt(cod)Cl2, 3 mol% of AgNTf2, and 3 eq of water in toluene at 100°C, and these conditions were successfully applied to the synthesis of a wide variety of α-aryl-α-acyloxyketones. The mechanism of this reaction was evaluated in detail based on the results of isotope labeling experiments using H218O.
The trialkylborane/O2-mediated reaction of propargyl acetates having a tributylstannyl group at an alkyne terminus with aldehydes in a THF–H2O solvent system gave anti-δ,δ-disubstituted homoallylic alcohols with good to high diastereoselectivity. Intriguingly, two alkyl groups derived from trialkylborane were embedded into the reaction product. The trialkylborane plays a key role not only as a radical
由三烷基硼烷/ O 2介导的炔烃末端具有三丁基锡烷基的炔丙基乙酸酯与醛在THF-H 2 O溶剂体系中的反应可得到具有良好或高非对映选择性的抗-δ,δ-二取代均烯丙基醇。有趣的是,两个衍生自三烷基硼烷的烷基被嵌入反应产物中。三烷基硼烷不仅起自由基引发剂的作用,而且作为烷基自由基的来源也起着关键作用。