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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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Soo Min Kim Ji Hoon Park Youn Kyung Kang Young Keun Chung Prof. 《Angewandte Chemie (International ed. in English)》2009,48(25):4532-4535
Tying up loose ends : The reaction of bisallenes tethered with N‐(p‐tolylsulfonamide) in the presence of a cationic gold N‐heterocyclic carbene catalyst gave new cycloisomerization products, 6,7‐dimethyleneazabicyclo[3.1.1]heptanes, in high yields (see scheme; IPr=N,N′‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene).
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Hai‐Hua Lu Hui Liu Dr. Wei Wu Xu‐Fan Wang Liang‐Qiu Lu Wen‐Jing Xiao Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(12):2742-2746
Economical approach : The first organocatalytic asymmetric intramolecular hydroarylation of phenol‐ and aniline‐derived enals offers one of the most straightforward and atom‐economic approaches to enantioriched chromans and tetrahydroquinolines (up to 96 % ee; see scheme).
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Claire Kammerer Guillaume Prestat Dr. David Madec Dr. Giovanni Poli Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(17):4224-4227
Free to decide : Various 4‐(α‐styryl) γ‐lactams are synthesized in 61–88 % yield by a phosphine‐free palladium‐catalyzed carbopalladation/allylic alkylation domino sequence (see scheme). The cyclization is totally regio‐ and diastereoselective in favor of the 3,4‐trans‐disubstituted γ‐lactam. The process is successfully applied to the synthesis of a new aza analogue of the naturally occurring lignan (+)‐oxo‐parabenzlactone.
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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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Dehui Zhang Chengye Yuan Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(16):4088-4101
β‐Amino acid analogues : The nucleophilic addition of ethyl (diethoxyethyl)methylphosphinate to a variety of (S)‐(tert‐butanesulfinyl)imines leads to the isolation of two enantioenriched β‐aminophosphinates (>95 % ee; see scheme). Subsequent removal of the protecting groups through pivotal metal‐catalyzed thiophenolysis leads to optically pure ethyl β‐amino‐H‐phosphinates.
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Benito Alcaide Prof. Dr. Pedro Almendros Dr. Teresa Martínez del Campo Elena Soriano Dr. José L. Marco‐Contelles Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(8):1909-1928
Calculating cyclization : Theoretical work directed towards the elucidation of the mechanisms of the gold‐, palladium‐, and lanthanum‐catalyzed oxycyclizations (5‐exo versus 6‐endo versus 7‐endo) of γ‐allenols has been pursued in close relationship with the experimental study (Part 1, accompanying paper) and has corroborated the bench results to provide a complete study of the reactivity of γ‐allenols under different metal‐catalyzed conditions.
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Paolo Ranzieri Dr. Alberto Girlando Prof. Silvia Tavazzi Prof. Marcello Campione Prof. Luisa Raimondo Dr. Ivano Bilotti Dr. Aldo Brillante Prof. Raffaele G. Della Valle Prof. Elisabetta Venuti Prof. 《Chemphyschem》2009,10(4):657-663
Two 4T: Low‐frequency micro‐Raman spectroscopy coupled with lattice dynamics calculations is an invaluable tool for investigating polymorphism in organic semiconductors. The Raman spectra of the low‐temperature (LT) and high‐temperature (HT) polymorphs of α‐quaterthiophene (4T) are presented and interpreted (see picture). Raman mapping is applied to investigate the phase purity.
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Eric S. Schmidtmann Dipl.‐Chem. Martin Oestreich Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(25):4634-4638
Once difficult to obtain , the title compounds can be prepared in virtually enantiomerically pure form with a bis(triorganostannyl) zinc reagent (see scheme). Subsequent diastereoselective thermal (left) and Lewis acid promoted reactions (right) illustrate the synthetic potential of these compounds.
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Hak‐Suk Sim Xinhui Feng Jaesook Yun Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(8):1939-1943
Josi or Mandy? Asymmetric conjugate addition of diboron to acyclic enones catalyzed by copper affords chiral organoboronates that possess a boronate group at the β stereocenter with excellent chemical yields and enantioselectivities (see scheme). This method accommodates the structural variation of acyclic enones and provides access to highly functionalized chiral organoboronates in one step.
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Ji‐Ho Yoon Prof. Yun‐Je Lee Jeasung Park Dr. Taro Kawamura Dr. Yoshitaka Yamamoto Dr. Takeshi Komai Dr. Satoshi Takeya Dr. Sang Sup Han Dr. Jong‐Won Lee Prof. Yongjae Lee Prof. 《Chemphyschem》2009,10(2):352-355
Easy come, easy go: Hydroquinone forms a channel structure of cages with hydrogen‐bonded hexagons. These may provide an ideal route for the fast inclusion and facile release of hydrogen molecules (see figure), which can lead to reversible hydrogen storage under mild conditions.
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