烯烃炔丙基碳酸酯的分子内[Pd 2(dba)3 ] /三(2-呋喃基)膦催化的(dba =二亚苄基丙酮,PhCHCHCOCHCHPh)环化反应,我提供了烷基-1-烯基-(3-氮杂)双环[3.1.0] -己烷八良好收益。提出了钯级联序列I II III IV IV VII VIII。此外,手性炔碳酸盐如23,24和25允许的非对映选择性形成二环[3.1.0]己烷29,30和31, 分别。单萜的第一非对映选择性合成,( - ) - α-侧柏酮40示出了该方法的潜力。
烯烃炔丙基碳酸酯的分子内[Pd 2(dba)3 ] /三(2-呋喃基)膦催化的(dba =二亚苄基丙酮,PhCHCHCOCHCHPh)环化反应,我提供了烷基-1-烯基-(3-氮杂)双环[3.1.0] -己烷八良好收益。提出了钯级联序列I II III IV IV VII VIII。此外,手性炔碳酸盐如23,24和25允许的非对映选择性形成二环[3.1.0]己烷29,30和31, 分别。单萜的第一非对映选择性合成,( - ) - α-侧柏酮40示出了该方法的潜力。
of the triplebond results in either cyclopropanation of the double bond with bulky R groups (SiMe3, Ph) or formation of alkylidene-alkenyl five-membered heterocycles, resulting from a beta elimination process, with less bulky R groups (R = Me, CH2CH=CH2). The reaction can be applied to in situ desilylation in methanol and direct formation of vinylbicyclo[3.1.0]hexanes and to the formation of some
在作为催化剂前体的 RuCl(COD)Cp* 存在下,各种含 CCH 键的 1,6-烯炔与 N2CHSiMe3 的反应导致在室温下普遍形成具有高 Z 的链烯基双环 [3.1.0] 己烷- 烯基的立体选择性和烯基的顺式排列和初始双键取代基,对于该双键的 E 构型。立体化学是通过确定三种双环产物的 X 射线结构来建立的。与在三键的 C1 碳上带有 R 取代基的 1,6-烯炔的相同反应导致双键与庞大的 R 基团(SiMe3,Ph)的环丙烷化或形成亚烷基-烯基五元杂环,导致来自β消除过程,具有较小的R基团(R = Me, CH = CH2)。该反应可用于甲醇中的原位脱甲硅烷基化反应和乙烯基双环[3.1.0]己烷的直接形成以及由1,7-烯炔形成一些烯基双环[4.1.0]庚烷。烯基双环 [3.1.0] 己烷的催化形成也发生在烯炔和 N2CHCO2Et 或 N2CHPh 中。该反应可以理解为通过 Ru=CHSiMe3
Gold(I)-Catalyzed Cyclizations of 1,6-Enynes: Alkoxycyclizations andexo/endo Skeletal Rearrangements
Gold(I) complexes are the most active catalysts for alkoxy- or hydroxycyclization and for skeletalrearrangement reactions of 1,6-enynes. Intramolecular alkoxycyclizations also proceed efficiently in the presence of gold(I) catalysts. The first examples of the skeletalrearrangement of enynes by the endocyclic cyclization pathway are also documented. Iron(III) is also able to catalyze exo and endo
Palladium catalysed nucleophilic additions to 1,6-dienes and a 1,6-enyne lead to cyclization in preference to β-hydrogen insertion; a novel cyclization of a 1,6-enyne to a 1,2-dimethylenecyclopentane is also reported.
Gold-Catalyzed Intermolecular Addition of Carbonyl Compounds to 1,6-Enynes: Reactivity, Scope, and Mechanistic Aspects
作者:Mathias Schelwies、Ralph Moser、Adrian L. Dempwolff、Frank Rominger、Günter Helmchen
DOI:10.1002/chem.200901614
日期:2009.10.19
carbonyl compounds to enynes yielding 2‐oxabicyclo[3.1.0]hexanes with four stereogenic centers, is presented. The reaction proceeds with very high diastereoselectivity. The scope of the reaction has been investigated. In addition, experiments and DFT calculations concerning mechanistic aspects were carried out. The reaction course varies with the substitution pattern of the alkene moiety of the starting
完整介绍了最近发现的金(I)催化的反应,即羰基化合物与烯炔的环加成反应,生成带有四个立体异构中心的2-氧杂双环[3.1.0]己烷。反应以非常高的非对映选择性进行。已经研究了反应范围。此外,还进行了有关机械方面的实验和DFT计算。反应过程随起始烯炔的烯烃部分的取代方式而变化。支链烯烃生成2-氧杂双环[3.1.0]己烷;在末端取代的烯烃上引入两个羰基组分,得到六氢环戊[ d ] [1,3]二恶英。
On the Mechanism of the Puzzling “Endocyclic” Skeletal Rearrangement of 1,6-Enynes
作者:Noemí Cabello、Eloísa Jiménez-Núñez、Elena Buñuel、Diego J. Cárdenas、Antonio M. Echavarren
DOI:10.1002/ejoc.200700402
日期:2007.9
presence of gold(I) catalysts, whereas increasing electron-withdrawing character of substituents at C-4 leads to five-membered rings. Reactions of these simple enynes in the presence of PtCl4 as catalyst give exclusively exo-double skeletal rearrangements. Enynes substituted at the alkyne also react with AuI catalysts to give exclusively products of exo-double rearrangement. The different mechanisms