The propargyltitanium reagents derived from 1-alkylpropyne condensed with aldehydes to give α-allenyl alcohol regioselectively, while the allenyltitanium reagents generated from 1-alky1-1-butyne derivatives gave threo-β-acetylenic alcohols with high regio- and stereoselectivities. The course of the reaction was determined by the substitution pattern of starting alkynes. The similar reactions of metallated
Coordination of the alkyl‐substituted alkynes Me3SiC2CH2R (1: R=SiMe3; 2: R=N(SiMe3)2) to titanocene centres [Cp′2Ti] (Cp′=Cp, Cp*) yields stable alkyne complexes of the type Cp′2Ti(η2‐Me3SiC2CH2R) (3: Cp′=Cp, R=SiMe3; 5: Cp′=Cp, R=N(SiMe3)2; 6: Cp′=Cp*, R=SiMe3) that are not prone to alkyne/allene isomerisation. When reacting alkyne 2 with Cp*2TiCl2 and Mg formation of the complex Cp*2Ti(III)(η3‐Me3SiC2CH2) (7)
A Rapid Synthesis of Hydroxymethylacylfulvene (HMAF) Using the Allenic Pauson−Khand Reaction. A Synthetic Approach to Either Enantiomer of This Illudane Structure
作者:Kay M. Brummond、Jianliang Lu、Jeffrey Petersen
DOI:10.1021/ja000546l
日期:2000.5.1
An allenicPauson−Khandreaction has been employed in the preparation of (±)-hydroxymethylacylfulvene (HMAF), an anticancer agent that is currently in Phase II clinical trials for a variety of solid tumor types. The synthesis is effected in 11 steps from commercially available starting materials. In addition, an asymmetric route to the title compound has been established by intersecting the racemic
丙氨酸 Pauson-Khand 反应已用于制备 (±)-羟甲基酰基富烯 (HMAF),这是一种抗癌剂,目前正处于针对多种实体瘤类型的 II 期临床试验中。由市售起始材料分 11 个步骤进行合成。此外,通过将外消旋合成与对映体纯中间体交叉,建立了获得标题化合物的不对称途径。对映异构纯中间体的制备涉及烯炔系统的三取代烯烃的 Sharpless 不对称二羟基化 (AD)。这种方法只需通过改变 Sharpless AD 反应中的配体即可获得 HMAF 的两种对映异构体。报告了使用 Peterson 烯化或 Horner-Wadsworth-Emmons 协议从脂肪族酮立体有择合成 E 或 Z 三取代烯炔的优化条件。最后,更好地理解等离子 P−K r 的立体电子要求...
Regiospecific allylation of acetals with allylsilanes catalyzed by iodotrimethylsilane. Synthesis of homoallylethers
作者:Hideki Sakurai、Koshi Sasaki、Akira Hosomi
DOI:10.1016/0040-4039(81)80140-2
日期:1981.1
Allylation of acetals with allylsilanes is catalyzed by iodotrimethylsilane to give the corresponding homoallyl ethers, with regiospecific transposition of the allyl group.
缩醛与烯丙基硅烷的烯丙基化通过碘代三甲基硅烷催化,得到相应的均烯丙基醚,且烯丙基的区域特异性易位。
Synthesis of Naphthylpyridines from Unsymmetrical Naphthylheptadiynes and the Configurational Stability of the Biaryl Axis
作者:Fabian Fischer、Alexander F. Siegle、Marek Checinski、Christine Fischer、Karolin Kral、Richard Thede、Oliver Trapp、Marko Hapke
DOI:10.1021/acs.joc.5b02190
日期:2016.4.15
cycloaddition reaction between the corresponding naphthyldiyne and aceto- or benzonitrile. The heterobiaryl products have been isolated and investigated with respect to the configurational stability of their biaryl axis using dynamic chiral HPLC; subtle effects of the substitution pattern on the stability of the axis were observed. For several compounds the activation barriers (ΔG‡) of racemization were determined