31555-04-1Relevant articles and documents
Catalytic (3+2) Palladium-Aminoallyl Cycloaddition with Conjugated Dienes
Trost, Barry M.,Huang, Zhongxing
supporting information, p. 6396 - 6399 (2019/04/13)
We describe the design and application of tailored aminoallyl precursors for catalytic (3+2) cycloaddition with conjugated dienes via a Pd-aminoallyl intermediate. The new cycloaddition reactions override the conventional (4+3) selectivity of aminoallyl cation cycloaddition through a sequence of Pd-allyl transfer and ring closure. A variety of highly substituted or fused pyrrolidine rings were synthesized using the cycloaddition, and can further undergo [1,3] N-to-C rearrangement to five-membered carbocycles with a different palladium catalyst. The utility of the (3+2) cycloaddition is also demonstrated by the preparation of various derivatives from the bicyclic pyrrolidine products.
Synthesis of γ-acetoxy β-keto esters through regioselective hydration of γ-acetoxy-α,β-alkynoates
Pradhan, Tapas R.,Mendhekar, Kishor L.,Mohapatra, Debendra K.
, p. 5517 - 5531 (2015/06/16)
The Au(I)-catalyzed regioselective hydration of γ-acetoxy-α,β-acetylinic ester by the assistance of a neighboring carbonyl group has been developed. Varieties of simple primary, secondary, and tertiary γ-acetoxy-α,β-acetylinic esters, even those bearing sensitive functional group in the remote reaction sites, are selectively hydrated to the corresponding β-keto esters. The reaction tolerates a wide variety of other carboxylates, such as benzoates, propionates, acrylates, and pivalates, including chiral carboxylates with retention of the configuration. The broad substrate scope, including the derivatization of complex natural products and neutral and open air conditions, makes this atom economical approach very practical. 18O labeling experiments disclose that the oxygen transposition occurs from the carboxylate group to the triple bond, not from water.
Ruthenium-catalyzed asymmetric [2 + 2] cycloadditions between chiral acyl camphorsultam-substituted alkynes and bicyclic alkenes
Goodreid, Jordan,Villeneuve, Karine,Carlson, Emily,Tam, William
, p. 10002 - 10012 (2015/02/19)
Ruthenium-catalyzed asymmetric [2 + 2] cycloadditions between chiral acyl camphorsultam-functionalized alkynes and bicyclic alkenes were examined, providing adducts with complete exo stereoselectivity in good overall yield and enantioselectivity (up to 99% and 166:1, respectively), as well as appreciable diastereoselectivity (up to 163:1). The diastereoselectivity showed dependence on the solvent and temperature, as well as on the substitution pattern of the reacting alkyne and bicyclic alkene components. In general, higher diastereoselectivities were observed for reactions conducted in ethereal solvents and at lower temperatures between N-propynoyl camphorsultams and bicyclic alkenes.
Regiodivergent addition of carbon units to dual-activated alkynes for stereoselective construction of tetrasubstituted alkenes
Ueda, Masafumi,Matsubara, Hiroshi,Yoshida, Kin-Ichi,Sato, Aoi,Naito, Takeaki,Miyata, Okiko
supporting information; experimental part, p. 1789 - 1792 (2011/03/21)
The discovery of potential synthons and reagent systems that allow the selective synthesis of target compounds is crucial for advances to be made in organic synthesis. Development of a simple methodology for preparing both regioisomers from a single subst
SUBSTITUTED PARA-BIPHENYLOXYMETHYL DIHYDRO OXAZOLOPYRIMIDINONES, PREPARATION AND USE THEREOF
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Page/Page column 55, (2011/04/19)
The present invention relates to a series of substituted para-biphenyloxymethyl dihydro oxazolopyrimidinones of formula (I) as defined herein. This invention also relates to methods of making these compounds including novel intermediates. The compounds of
A sequential reaction process to assemble polysubstituted indolizidines, quinolizidines and quinolizidine analogues
Cai, Guorong,Zhu, Wei,Ma, Dawei
, p. 5697 - 5708 (2007/10/03)
The ω-iodo-α,β-alkynoates and their ketone, sulfone or phosphonate analogues react with δ-chloropropylamines in MeCN assisted with K2CO3 to undergo a sequential SN2/Michael addition/SN2/SN2 reaction p
Study on the reactivity of the alkyne component in ruthenium-catalyzed [2 + 2] cycloadditions between an alkene and an alkyne
Jordan, Robert W.,Villeneuve, Karine,Tam, William
, p. 5830 - 5833 (2007/10/03)
The ruthenium-catalyzed [2 + 2] cycloadditions of norbornadiene with a variety of alkynes have been investigated. Electronic effect of the alkyne component has shown to play an important role on the rate of the cycloaddition, and the reactivity of the alkyne component increases dramatically as the alkyne becomes more electron deficient. Increase in the steric bulk of the alkyne component decreases the reactivity of the alkyne component. It was also found that chelation effect of propargylic alcohols greatly enhanced the reactivity of the alkyne component in the ruthenium-catalyzed [2 + 2] cycloadditions.
2-Alkynyl-and 2-alkenyl-pyrazolo-[4,3-e]-1,2,4-triazolo-[1,5-c]-pyrimidine adenosine A2a receptor antagonists
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Page 58, (2008/06/13)
Compounds having the structural formula I or a pharmaceutically acceptable salt thereof, wherein R is R1, R2, R3, R4 and R5 are H, alkyl or alkoxyalkyl; R6 is H, alkyl, hydroxyalkyl or —CH2F; R7, R8 and R9 are H, alkyl, alkoxy, alkylthio, alkoxyalkyl, halo or —CF3; and Z is optionally substituted aryl, heteroaryl or heteroaryl-alkyl are disclosed. Also disclosed is the use of compounds of formula I in the treatment of central nervous system diseases, in particular Parkinson's disease, alone or in combination with other agents for treating Parkinson's disease, and pharmaceutical compositions comprising them.
Catalytic alkynylation of ketones and aldehydes using quaternary ammonium hydroxide base
Ishikawa, Teruhiko,Mizuta, Tomohiro,Hagiwara, Kumiko,Aikawa, Toshiaki,Kudo, Takayuki,Saito, Seiki
, p. 3702 - 3705 (2007/10/03)
Catalytic alkynylation of diverse ketones and aldehydes using nonmetallic benzyltrimethylammonium hydroxide or a basic resin of the hydroxide type in DMSO is described. Aliphatic or alicyclic carbonyl partners gave satisfactory results, whereas aromatic o
Microwave thermolysis IV: Selective deprotection of MPM ethers using clay supported ammonium nitrate 'clayan' in dry media
Yadav,Meshram,Sudershan Reddy,Sumithra
, p. 3043 - 3046 (2007/10/03)
Selective deprotection of (4-methoxyphenyl)-methyl (MPM) ethers using clay supported ammonium nitrate under microwave irradiation is described. The use of expensive reagents and problems associated with slurry reactions are avoided.
