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Toshimichi Ohmura Dr. Yuta Takasaki Hideki Furukawa Michinori Suginome Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(13):2372-2375
Changing places : Intramolecular B(pin)/H exchange took place in the presence of a platinum–phosphane catalyst, giving synthetically useful cis‐β‐methyl‐substituted alkenylboronates stereoselectively (see scheme; B(pin)=4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl).
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Jun Shi Hiroki Shigehisa Dr. Carlos A. Guerrero Ryan A. Shenvi Chuang‐Chuang Li Dr. Phil S. Baran Prof. 《Angewandte Chemie (International ed. in English)》2009,48(24):4328-4331
One stereocenter makes all the difference : The synthesis and biological evaluation of 17‐epi‐cortistatin A is reported from a common intermediate used to procure natural cortistatin A. The synthesis features a unique stereocontrolled Raney‐Ni reduction process that can be employed to reliably produce both α‐ and β‐configured D‐ring aryl steroids. Biological evaluations of these “cortalogs” are reported for the first time.
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Frank U. Richter 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(21):5200-5202
Whereas 1‐organyl‐phospholanes and 1‐organyl‐2,3‐dihydro‐1H‐phospholes catalyze isocyanate oligomerization, the reaction of isocyanates with 1‐organyl‐2,5‐dihydro‐1H‐phospholes results in the formation of 1,3‐dienes and a novel class of P‐heterocycles, 1,4,2‐diazaphospholidine‐3,5‐diones. Isothiocyanates and carbodiimides exhibit analogous behavior. The resultant species readily form P‐oxides, P‐sulfides (see picture), and quaternary onium salts.
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Chen Zhao Yuan Kou Prof. Dr. Angeliki A. Lemonidou Prof. Dr. Xuebing Li Dr. Johannes A. Lercher Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(22):3987-3990
Oil and water : A new energy‐efficient and atom‐economical catalytic route for the production of alkanes and methanol by upgrading the phenolic fraction of bio‐oil has been developed. The one‐pot aqueous‐phase hydrodeoxygenation process is based on two catalysts facilitating consecutive hydrogenation, hydrolysis, and dehydration reactions.
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Andreas Lorbach Dipl.‐Chem. Michael Bolte Dr. Haiyan Li Hans‐Wolfram Lerner Dr. Max C. Holthausen Prof. Dr. Frieder Jäkle Prof. Dr. Matthias Wagner Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(25):4584-4588
Building bridges : The title compound forms an unprecedented polymeric structure with bridging B–H–B three‐center two‐electron bonds in the solid state. This organoborane serves as an efficient precursor for the preparation of boron‐doped π‐conjugated polymers by hydroboration polymerization with a functionalized 1,4‐diethynylbenzene (see picture). These polymers form thin films that show intense green luminescence.
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Romas Kudirka Sean K. J. Devine Christopher S. Adams David L. Van Vranken Prof. 《Angewandte Chemie (International ed. in English)》2009,48(20):3677-3680
As easy as 1, 2, 3 : A palladium‐catalyzed three‐component coupling generates α,β‐unsaturated γ‐amino acids in a single step (see scheme). The reaction is believed to involve migration of a vinyl substituent to a highly electrophilic palladium carbene. Unlike previous synthetic approaches, this synthesis provides access to γ‐amino acids with non‐natural side chains.
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Hsian‐Wen Wang Zhi‐Chang Liu Chih‐Hsien Chen Dr. Tsong‐Shin Lim Prof. Wunshain Fann Prof. Chih‐Gang Chao Jian‐Yuan Yu Shern‐Long Lee Chun‐hsien Chen Prof. Shou‐Ling Huang Tien‐Yau Luh Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(23):5719-5728
You can append on me! Porphyrin‐appended polynorbornenes derived from 5,6‐endo‐fused N‐arylpyrrolidenonorbornenes have been shown to have coherently aligned pendant groups that exhibit exciton coupling and fluorescence quenching in the absorption and emission profiles (see figure).
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Jorge Bordello Belén Reija Dr. Wajih Al‐Soufi Prof. Dr. Mercedes Novo Prof. Dr. 《Chemphyschem》2009,10(6):931-939
Buckle up! The dimerization of small fluorescent guests is strongly enhanced in presence of a cyclodextrin host. The host cavity acts like a belt to assist the self‐assembly of guests (see picture). Small variations in the guest structure have significant influence on the stability and geometry of the aggregates.
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Shaobin Miao Dr. Anthony L. Appleton Nancy Berger Stephen Barlow Dr. Seth R. Marder Prof. Kenneth I. Hardcastle Dr. Uwe H. F. Bunz Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(20):4990-4993
A new relative of pentacene : The dialkynylated tetraazapentacene (see figure) was prepared by a two‐step synthesis from the corresponding quinone derivative. The heteroacene is an air‐stable, dark‐blue, crystalline material and is of great interest as a potential organic n‐electron‐transport material.
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Reiko Jennerjahn Irene Piras Ralf Jackstell Dr. Robert Franke Dr. Klaus‐Diether Wiese Dr. Matthias Beller Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(26):6383-6388
A novel selective palladium catalyst system based on bidentate 2,2′‐heteroarylarylphosphines and p‐TsOH has been developed for hydroformylation reactions (see scheme). By applying optimal conditions good to excellent regioselectivity is obtained for the hydroformylation of aliphatic and aromatic olefins. It is shown that a low acid concentration is crucial for obtaining high degrees of the linear isomer.
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Yann Ferrand Dr. Emmanuel Klein Dr. Nicholas P. Barwell Matthew P. Crump Dr. Jesus Jiménez‐Barbero Prof. Cristina Vicent Dr. Geert‐Jan Boons Prof. Sampat Ingale Anthony P. Davis Prof. 《Angewandte Chemie (International ed. in English)》2009,48(10):1775-1779
Changing employment : Receptor 1 binds β‐N‐acetylglucosaminyl (β‐GlcNAc) up to 100 times more strongly than it does glucose. This synthetic lectin shows affinities similar to wheat germ agglutinin (WGA), a natural lectin used to bind GlcNAc. Remarkably, 1 is more selective than WGA. It favors especially the glycoside unit in glycopeptide 2 , a model of the serine‐O‐GlcNAc posttranslational protein modification.
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Yasunori Yamamoto Dr. Kazunori Kurihara Dr. Norio Miyaura Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(24):4414-4416
Ligand design by‐pam : A ruthenium‐catalyzed asymmetric arylation of aldehydes with arylboronic acids has been developed, giving chiral diarylmethanols in good yields. The use of a chiral bidentate phosphoramidite ligand ((R,R)‐Me‐bipam) led to excellent enantioselectivities.