نتایج جستجو برای: carbonates

تعداد نتایج: 9055  

Journal: :Chemical communications 2011
Ji-Rong Huang Hai-Lei Cui Jie Lei Xun-Hao Sun Ying-Chun Chen

The first Lewis base-catalysed chemoselective asymmetric N-allylic alkylation of enamides with Morita-Baylis-Hillman carbonates has been developed, which affords multifunctional products in moderate to high enantioselectivity (up to 92% ee).

Journal: :Organic & biomolecular chemistry 2012
Sandro Cacchi Giancarlo Fabrizi Eleonora Filisti Antonella Goggiamani Antonia Iazzetti Loredana Maurone

A novel palladium-catalyzed approach to 2-amino ketones from arylpropargylic carbonates bearing neutral, electron-rich, and electron-poor aromatic rings and cyclic secondary amines containing useful functional groups such as cyano, chloro, and bromo substituents has been developed.

Journal: :Chemical communications 2006
P Andrew Evans Kwong Wah Lai Hai-Ren Zhang John C Huffman

The regioselective and enantiospecific rhodium-catalyzed allylic amination of secondary allylic carbonates with N3-benzoyl thymine in conjunction with a stereoselective free radical cyclization provides a convenient method for the construction of a new conformationally rigid nucleoside.

2008
Ted A. McConnaughey David Paul Gillikin

Mollusk shells contain many isotopic clues about calcification physiology and environmental conditions at the time of shell formation. In this review, we use both published and unpublished data to discuss carbon isotopes in both bivalve and gastropod shell carbonates. Land snails construct their shells mainly from respired CO2, and shell δC reflects the local mix of C3 and C4 plants consumed. S...

Journal: :Chemical communications 2011
Hyun Chul Cho Han Sol Lee Jiseul Chun Sang Moon Lee Hae Jin Kim Seung Uk Son

Tubular microporous organic networks bearing imidazolium salts (T-IM) were prepared by Sonogashira coupling of tetrakis(4-ethynylphenyl)methane and diiodoimidazolium salts, which showed promising catalytic activities in heterogeneous conversion of CO(2) into cyclic carbonates.

Journal: :Organic & biomolecular chemistry 2008
Caroline Joannesse Carmen Simal Carmen Concellón Jennifer E Thomson Craig D Campbell Alexandra M Z Slawin Andrew D Smith

The structural requirements of amidines necessary to act as efficient O- to C-carboxyl transfer agents are delineated and the scope of this process outlined through its application to a range of oxazolyl, benzofuranyl and indolyl carbonates.

Journal: :Chemical communications 2012
Tadashi Ema Yuki Miyazaki Shohei Koyama Yuya Yano Takashi Sakai

We have developed a very active bifunctional porphyrin catalyst showing a high turnover number (TON = 103,000) for the synthesis of cyclic carbonates from CO(2) and epoxides under solvent-free conditions.

Journal: :Aldrichimica acta 2016
Yumei Xiao Hongchao Guo Ohyun Kwon

Recent advances in chiral-phosphine-catalyzed asymmetric annulation reactions; including annulations of allenes, alkynes, Morita-Baylis-Hillman (MBH) carbonates, and ketenes; and their applications in the synthesis of bioactive molecules and natural products are reviewed.

ژورنال: علوم آب و خاک 2013
حسین پور, علیرضا, رئیسی, فایز, متقیان, حمیدرضا, محمدی, جهانگرد,

Studying the distribution of Zn in the soils allows investigating their mobility and bioavailability. In this research, 10 calcareous soil samples were selected, and sewage sludge-amended (1% w/w) and -unamended (control) soils were incubated for 1 month. Before planting, fractions of Zn were determined, three seeds of wheat were planted in each pot and after 8 weeks, they were harvested. Resul...

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