Nickel-Catalyzed Regioselective Hydroalkylation of 1,3-Dienes with Hydrazones

2019 ◽  
Author(s):  
Leiyang Lv ◽  
Dianhu Zhu ◽  
Zihang Qiu ◽  
Jianbin Li ◽  
Chao-Jun Li
Keyword(s):  
Catalytic Method ◽  
Unsaturated Hydrocarbons ◽  
Carbon Nucleophiles ◽  
Aryl Aldehydes ◽  
Aldehydes And Ketones ◽  
Sterically Hindered

Hydroalkylation of unsaturated hydrocarbons with unstablized carbon nucleophiles is difficult and remains a major challenge. The disclosed examples so far mainly focused on the involvement of heteroatom and/or stabilized carbon nucleophiles as efficient reaction partners. Reported here is an unprecedented regioselective nickel-catalyzed hydroalkylation of 1,3-dienes with hydrazones, generated in situ from abundant aryl aldehydes and ketones and acted as both the sources of unstabilized carbanions and hydride. With this strategy, both terminal and sterically hindered internal dienes are hydroalkylated efficiently in a highly selective manner, thus providing a novel and reliable catalytic method to construct challenging C(sp3)-C(sp3) bonds.

Nickel-Catalyzed Regioselective Hydroalkylation of 1,3-Dienes with Hydrazones

2019 ◽  
Author(s):  
Leiyang Lv ◽  
Dianhu Zhu ◽  
Zihang Qiu ◽  
Jianbin Li ◽  
Chao-Jun Li
Keyword(s):  
Catalytic Method ◽  
Unsaturated Hydrocarbons ◽  
Carbon Nucleophiles ◽  
Aryl Aldehydes ◽  
Aldehydes And Ketones ◽  
Sterically Hindered

Hydroalkylation of unsaturated hydrocarbons with unstablized carbon nucleophiles is difficult and remains a major challenge. The disclosed examples so far mainly focused on the involvement of heteroatom and/or stabilized carbon nucleophiles as efficient reaction partners. Reported here is an unprecedented regioselective nickel-catalyzed hydroalkylation of 1,3-dienes with hydrazones, generated in situ from abundant aryl aldehydes and ketones and acted as both the sources of unstabilized carbanions and hydride. With this strategy, both terminal and sterically hindered internal dienes are hydroalkylated efficiently in a highly selective manner, thus providing a novel and reliable catalytic method to construct challenging C(sp3)-C(sp3) bonds.

Synthesis of Highly SubstitutedN-Hydroxyindoles through 1,5-Addition of Carbon Nucleophiles to In Situ Generated Unsaturated Nitrones

2006 ◽  
Vol 118 (32) ◽  
pp. 5490-5494 ◽  
Author(s):  
K. C. Nicolaou ◽  
Anthony A. Estrada ◽  
Sang Hyup Lee ◽  
Graeme C. Freestone
Keyword(s):  
Carbon Nucleophiles

Growth and Characterization of Cobalt-filled Carbon Nanotubes Prepared by a Simple Catalytic Method

2003 ◽  
Vol 776 ◽  
Author(s):  
Xicheng Ma ◽  
Yuanhua Cai ◽  
Xia Li ◽  
Ning Lun ◽  
Shulin Wen
Keyword(s):  
Carbon Nanotubes ◽  
Metallic Nanoparticles ◽  
Low Cost ◽  
Catalytic Method ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
One Step

AbstractHigh-quality cobalt-filled carbon nanotubes (CNTs) were prepared in situ in the decomposition of benzene over Co/silica-gel nano-scale catalysts. Unlike the previous reports, the catalysts needn't be pre-reduced prior to the forming of Co-filled CNTs, thus the advantage of this method is that Co-filled CNTs can be produced in one step, at a relatively low cost. Transmission electron microscopy (TEM) investigation showed that the products contained abundance of CNTs and most of them were filled with metallic nanoparticles or nanorods. High-resolution TEM (HRTEM), selected area electron diffraction (SAED) patterns and energy dispersive X-ray spectroscopy (EDS) confirmed the presence of Co inside the nanotubes. The encapsulated Co was further identified always as high temperature alpha-Co phase with fcc structure, which frequently consists of twinned boundaries and stacking faults. Based on the experimental results, a possible growth mechanism of the Co-filled CNTs was proposed.

Studies of Emissions from Oil Fires

1999 ◽  
Vol 1999 (1) ◽  
pp. 541-547 ◽  
Author(s):  
Mervin F. Fingas ◽  
Patrick Lambert ◽  
Ken Li ◽  
Zhendi Wang ◽  
Francine Ackerman ◽  
...  
Keyword(s):  
Crude Oil ◽  
Ground Level ◽  
Health Concern ◽  
Exposure Level ◽  
Emission Data ◽  
Combustion Gases ◽  
Aldehydes And Ketones ◽  
Polycyclic Aromatic ◽  
Exposure Levels

ABSTRACT Over 35 meso-scale burns were conducted to study various aspects of diesel and crude oil burning in situ. Extensive sampling and monitoring of these burns were conducted at downwind stations, upwind stations, and in the smoke plume. Particulate samples were taken in air and analyzed for polycyclic aromatic hydrocarbons (PAHs). PAHs were found to be lower in the soot than in the starting oil, although higher concentrations of the larger molecular PAHs were found in the soot and residue, especially for diesel burns. Particulates in the air were measured by several means, and were found to be greater than recommended exposure levels up to 500 meters downwind at ground level, depending on the size and type of fire. Diesel fires emit much more particulate matter and have longer exposure zones. Combustion gases, including carbon dioxide and carbon monoxide, were below exposure level maximums. Volatile organic compound (VOCs) emissions were measured, but the levels were less than from an evaporating crude oil spill. Over 140 compounds were identified and quantified. Carbonyls, including aldehydes and ketones, were found to be below human health concern levels. Emission data from over 30 experimental burns were used to develop prediction equations for over 150 specific compounds or emission categories. These were used to calculate safe distances and levels of concern for a standard burn size of 500 square meters, an amount that would typically be contained in a boom. The safe distance for a crude oil burn of this size is about 500 m and for a diesel burn, much farther.

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