Highly efficient synthesis of alka-1,3-dien-2-yltitanium compounds from alka-2,3-dienyl carbonates. A new, practical synthesis of 1,3-dienes and 2-iodo-1,3-dienes
摘要:
Treatment of carbonates of alka-2,3-dien-1-ols 2 with (eta(2)-propene)Ti(O-i-Pr)(2) (I) resulted in oxidative addition to afford 1,3-dien-2-yltitanium compounds 3, which react readily with electrophiles such as H+, I-2 and aldehydes. The reaction with H+ and I-2 proceeds highly regioselectively, thus providing an efficient and practical method for synthesis of 1,3-dienes and 2-iodo-1,3-dienes. Copyright (C) 1996 Elsevier Science Ltd.
Novel synthesis of 1,3-dienes from 1-alkenes via /ldene/rd reaction with pummerer rearrangement product: a short synthesis of the sex pheromone of the red bollworm moth
A Pummererrearrangement product, 4-chlorophenylthiomethyl trifluoroacetate (6), obtained from 4-chlorophenyl methyl sulfoxide (5) and trifluoroacetic anhydride, reacted with 1-alkenes in trifluoroacetic acid to give the ene products 8, which were readily converted into the terminal 1,3-dienes 10 by oxidation and subsequent pyrolysis. Using this method, 9,11-dodecadien-1-yl acetate (12), a sex pheromone
Up the Hill: Selective Double-Bond Isomerization of Terminal 1,3-Dienes towards Z-1,3-Dienes or 2Z,4E-Dienes
作者:Florian Pünner、Anastasia Schmidt、Gerhard Hilt
DOI:10.1002/anie.201107512
日期:2012.1.27
different cobalt catalyst systems led to the selectiveisomerization of 1,3‐dienes. In the case of the [CoBr2(py‐imine)]‐catalyzed reaction, the Z‐1,3‐diene was formed in a highly selective manner (see scheme). When the catalyst precursor [CoBr2(dpppMe2)] was applied, a double‐bond migration and selectiveisomerizationtowards the 2Z,4E‐configured 2,4‐dienes were observed
Photoinduced Palladium-Catalyzed Carbofunctionalization of Conjugated Dienes Proceeding via Radical-Polar Crossover Scenario: 1,2-Aminoalkylation and Beyond
作者:Kelvin Pak Shing Cheung、Daria Kurandina、Tetsuji Yata、Vladimir Gevorgyan
DOI:10.1021/jacs.0c03993
日期:2020.6.3
A photoinduced palladium-catalyzed 1,2-carbofunctionalization of conjugateddienes has been developed. This mild modular approach, which does not require employment of exogeneous photosensitizers and external oxidants, allows for efficient and highly regio- and ste-reoselective synthesis of a broad range of allylic amines from readily available 1,3-dienes, alkyl iodides, and amines. Employment of O-
The dicarbonylation of 1,3‐butadiene to adipic acid derivatives offers the potential for a more cost‐efficient and environmentally benign industrial process. However, the complex reaction network of regioisomeric carbonylation and isomerization pathways, make a selective and direct transformation particularly difficult. Here, we report surprising solvent effects on this palladium‐catalysed process
将1,3-丁二烯二羰基化为己二酸衍生物可为更具成本效益和环境友好的工业生产提供潜力。然而,区域异构体羰基化和异构化途径的复杂反应网络使得选择性和直接转化特别困难。在这里,我们报道了在存在1,2-双-二叔丁基膦膦-二甲苯(d t bpx)配体的情况下,钯催化的这一过程产生了令人惊讶的溶剂影响,这些配体允许由1,3-丁二烯,碳形成己二酸酯二酯。一氧化碳和甲醇,在可扩展条件下具有97%的选择性和100%的原子经济性。在最佳条件下,可以以高至极好的收率获得各种1,2-和1,3-二烯的二酯和三酯。
Copper-Catalyzed Regioselective Hydroalkylation of 1,3-Dienes with Alkyl Fluorides and Grignard Reagents
Copper complexes generated in situ from CuCl2, alkylGrignardreagents, and 1,3‐dienes play important roles as catalytic active species for the 1,2‐hydroalkylation of 1,3‐dienes by alkylfluorides through CF bond cleavage. The alkyl group is introduced to an internal carbon atom of the 1,3‐diene regioselectively, thus giving rise to the branched terminal alkene product.