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451398

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Franz, A.K. Woerpel, K.A.
Journal of the American Chemical Society, 121, 949-949 (1999)
J R Baker et al.
Organic letters, 9(1), 45-48 (2006-12-29)
[reaction: see text] A key structural feature of the Neocarzinostatin chromophore is a reactive epoxydiyne. We present here a new method for the preparation of epoxydiynes by the addition of an allenyl zinc bromide to a propargylic ketone.
Yasuhiro Inui et al.
Chemical & pharmaceutical bulletin, 57(10), 1158-1160 (2009-10-06)
Asymmetric intermolecular hydroacylation between salicylaldehyde (1) and 1,5-hexadiene (2) using a combination of [RhCl(C(8)H(14))(2)](2) (0.10 eq), (S)-BINAP (0.10 eq), and ZnBr(2) (0.20 eq) afforded an enantiomerically enriched hydroacylated product iso-3 of 84% ee, along with an achiral product normal-3.
Yu Sung Chun et al.
Organic letters, 11(15), 3414-3417 (2009-07-04)
The in situ generated Blaise reaction intermediate, a zinc bromide complex of beta-enaminoester, reacts with various unactivated terminal alkynes and an internal alkyne under mild conditions to afford alpha-vinylated beta-enaminoesters in good to excellent yields.
Fernando Ferreira et al.
Nucleosides, nucleotides & nucleic acids, 24(5-7), 1009-1013 (2005-10-27)
An oligonucleotide protected with N-(trimethylsilyloxycarbonyl) (Teoc) and P-(trimethylsilylethanol) (Tse) groups was synthesized and deprotected by a single ZnBr2 treatment. Finally it was released from the solid support by cleavage of a disulfide linkage with TCEP. The olgonucleotide was obtained without
Thomas Hameury et al.
Organic letters, 11(11), 2397-2400 (2009-05-09)
A diastereodivergent addition of allenylzincs to aryl glyoxylates was observed depending on the method used for the preparation of the allenylzinc reagent. The allenylzincs were prepared from propargylic benzoates in the presence of a palladium catalyst or by metalation of
Carles Rodríguez-Escrich et al.
Organic letters, 9(6), 989-992 (2007-02-14)
The key THF derivative (9a) for an enantioselective synthesis of amphidinolide X/Y was obtained from 1a via a selenoetherification reaction. In fact, among the cyclization methods investigated, the highest yield and stereocontrol were achieved at -78 degrees C with PhSeCl/EtiPr2N
Yang Yu et al.
Preparative biochemistry & biotechnology, 37(4), 381-387 (2007-09-13)
Zinc bromide catalyzes the three component condensation reaction of an aldehyde, urea, and beta-ketoester or beta-diketone under solvent-free conditions to afford the corresponding dihydropyrimidinones (DHPMs) with moderate to high yields in short reaction time. The present method is very effective
Kathleen Simis et al.
Drug development and industrial pharmacy, 34(9), 936-942 (2008-09-19)
Application of the Staccato system to liquid drugs presents unique technological challenges. Liquids, such as nicotine, do not form physically stable films on vaporization substrates. We identified two thermally reversible zinc halides (ZnCl2 and ZnBr2) that complex with nicotine in
Facile preparation of phenyl 1-thioglycosides of partially methylated maltooligosaccharides by restricted thiolysis of fully methylated cyclodextrins.
N Sakairi et al.
Carbohydrate research, 280(1), 139-143 (1996-01-04)
Chutian Shu et al.
The Journal of organic chemistry, 75(19), 6677-6680 (2010-09-08)
The key Pd-catalyzed cross-coupling of aryl bromides or triflates and cyclopropylmagnesium bromide in the presence of substoichiometric amounts of zinc bromide produces cyclopropyl arenes in good to excellent yields. The cross-coupling of other alkyl, cycloalkyl, and aryl Grignard reagents with
Biswajit Kalita et al.
Chemical communications (Cambridge, England), (36)(36), 4291-4293 (2008-09-20)
Benzylic and allylic hydrocarbons are selectively converted to the corresponding sulfonamides by a ZnBr2-H2O-catalyzed reaction with PhI=NTs; saturated adamantane is aminosulfonated at the tertiary C-H bond.
Direct synthesis of alkynylstannanes: ZnBr2 catalyst for the reaction of tributyltin methoxide and terminal alkynes.
Kensuke Kiyokawa et al.
Angewandte Chemie (International ed. in English), 50(44), 10393-10396 (2011-09-15)
Ganesan Gobi Rajeshwaran et al.
Organic letters, 13(6), 1418-1421 (2011-02-24)
A synthesis of staurosporine aglycon and its analogs was achieved in a 28-36% overall yield starting from 2-methylindole. The prominent key steps for the synthesis of the indolocarbazole alkaloids involved electrocyclization and nitrene insertion reactions.
C E Klopfenstein et al.
Annales francaises d'anesthesie et de reanimation, 17(7), 747-749 (1998-09-29)
We report a serious dysfunction of 19 halothane vaporisers Vapor 19.3 (Dräger) which delivered a much higher concentration of agent than indicated on the dial. This inaccuracy was linked to a major corrosion of the inner layers of the vaporiser
Ramesh Kaul et al.
The Journal of organic chemistry, 69(18), 6131-6133 (2004-09-18)
Chemoselective hydrolysis of tert-butyl esters in the presence of other acid-labile groups has been explored by employing alpha-amino esters and ZnBr(2) in DCM. Although N-Boc and N-trityl groups were found to be labile, PhF protected amines were compatible with these
Isabelle Aillaud et al.
Molecules (Basel, Switzerland), 15(11), 8144-8155 (2010-11-13)
A methodological study devoted to the Mannich-like multicomponent synthesis of the antiplatelet agent (±)‑clopidogrel (7) and the ethyl ester analogue 6 is described. The process involves the formation of 2-chlorophenyl zinc bromide (2) and its subsequent reaction with an alkyl
Frederic G Buono et al.
Organic letters, 10(23), 5325-5328 (2008-11-05)
Kinetic studies using reaction calorimetry were conducted under synthetically relevant conditions to study the effect of additives in the cyanation of bromobenzene catalyzed by palladium complexes. This work demonstrates that the addition of a catalytic amount of ZnBr(2) facilitates the
Teiichi Murakami et al.
Carbohydrate research, 343(8), 1297-1308 (2008-04-15)
Reactions of O-benzoylated glucopyranosyl halide (I, Br), isolated or generated in situ from per-benzoylated glucose (8a) and trimethylsilyl halide, with various alcohols were efficiently promoted by zinc halide (Cl, Br) or N-bromosuccinimide with a catalytic ZnI(2) to give the corresponding
A E Hassan et al.
Nucleosides, nucleotides & nucleic acids, 19(7), 1123-1134 (2000-09-22)
Efficient methods for the synthesis of 6-methylpurine (3), 9-(2-deoxy-beta-D-erythro-pentofuranosyl)-6-methylpurine (8), and 6-methyl-9-beta-D-ribofuranosylpurine (5) are described. Methodology involving the (Ph3P)4Pd catalyzed cross-coupling reaction of CH3ZnBr with several different 6-chloropurine derivatives is described in high yield. This methodology now provides a facile
Daniela Andrei et al.
The Journal of organic chemistry, 71(1), 405-408 (2006-01-04)
[reaction: see text] The 1-fluoro-1-haloalkenes undergo Pd-catalyzed Negishi cross-couplings with primary alkylzinc bromides to give multisubstituted fluoroalkenes. The alkylation was trans-selective giving pure Z-fluoroalkenes in most cases. The highest yields were obtained with Pd2(dba)3 and PdCl2(dppb) catalysts but the best
Toshiaki Sasada et al.
Chemistry (Weinheim an der Bergstrasse, Germany), 17(34), 9385-9394 (2011-07-23)
The [5+1] annulation of enamidines, which were prepared from functionalized silanes, organolithium compounds and two nitriles, with N,N-dimethylformamide dialkyl acetals as the C1 unit is described, leading to the synthesis of tri- and tetrasubstituted pyrimidine derivatives under catalyst- and solvent-free
Ruixue Deng et al.
Organic letters, 9(25), 5207-5210 (2007-11-10)
A number of indenes have been prepared in good yields by treating o-bromobenzyl zinc bromide 1 with various terminal and internal alkynes in the presence of a nickel catalyst. The nickel-catalyzed carboannulation reaction was successfully extended to the synthesis of
S Takeda et al.
Chemical & pharmaceutical bulletin, 48(7), 1097-1100 (2000-08-03)
The alpha,alpha-gem-difluorination of 2',4'-difluoro-alpha-(methylthio)acetophenone (1a) with N-fluoropyridinium salts gave 2',4',alpha,alpha-tetrafluoro-alpha-(methylthio)acetophenone (3a). This reaction was accelerated by the addition of zinc chloride, zinc bromide or anhydrous iron(III) chloride, and higher yields than the reaction without additives were obtained. The gem-difluorination reaction
Erik Lundberg et al.
Journal of structural biology, 155(3), 445-457 (2006-05-26)
The transthyretin-related protein (TRP) family comprises proteins predicted to be structurally related to the homotetrameric transport protein transthyretin (TTR). The function of TRPs is not yet fully established, but recent data suggest that they are involved in purine catabolism. We
Yejian Han et al.
Organic letters, 13(4), 588-591 (2011-01-12)
An efficient and versatile ZnBr(2)-catalyzed Diels-Alder/carbocyclization cascade reaction has been developed for construction of highly functionalized cis-hydrindanes (70-96% yields with high diastereoselectivity), and it has been successfully utilized in the synthesis of the aglycon of dendronobiloside A.
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