Synthesis of 3-trialkylsilyl pyrazoles from β-oxo acylsilanes
摘要:
The synthesis of beta -oxo acylsilanes via cyclic sulfates is described and applied to carbohydrates. These compounds are used for the synthesis of new silylated pyrazoles linked to a carbohydrate moiety by the addition of hydrazines. The regiochemistry of the reaction was determined by NMR analyses (H-1/C-13 and H-1/N-15 correlations). (C) 2000 Elsevier Science Ltd. All rights reserved.
Aluminum-Catalyzed Formation of Functional 1,3,2-Dioxathiolane 2-Oxides from Sulfur Dioxide: An Easy Entry towards<i>N</i>-Substituted Aziridines
作者:Victor Laserna、Eddy Martin、Eduardo C. Escudero-Adán、Arjan W. Kleij
DOI:10.1002/adsc.201600831
日期:2016.12.7
Aluminum(III) complexes derived from aminotriphenolate ligands are shown to be excellent catalysts for the formation of cyclic sulfites from a range of (functionalized) terminal and internal epoxides, and ex situ generated sulfur dioxide. The developed catalytic protocol is characterized by its operational simplicity, wide scope in epoxide reaction partners, good to excellent isolated yields and mild
Novel reagents containing hypervalent iodine and their use for electrophilic additions to olefins
作者:Nikolai S. Zefirov、Viktor V. Zhdankin、Yu.V. Dan`kov、Viktor D. Sorokin、Vladimir N. Semerikov、Anatoly S. Koz`min、Ronald Caple、Bruce A. Berglund
DOI:10.1016/s0040-4039(00)84887-x
日期:1986.1
A series of novel I(III) containing reagents have been developed and their electrophilic reactions with olefins giving vic-disubstituted derivatives (including vic-ditriflates) are described.
A convenient synthesis of 1-(diethoxyphosphoryl)cyclopropanecarboxylates
作者:Henryk Krawczyk、Katarzyna Wąsek、Jacek Kędzia、Jakub Wojciechowski、Wojciech M Wolf
DOI:10.3998/ark.5550190.0011.913
日期:——
An efficient synthesis of a series of 1-(diethoxyphosphoryl)cyclopropancarboxylates was accomplished by the reaction of terminal 1,2-diols cyclic sulfates with triethylphosphonoacetate. The stereochemistry of 2-benzyloxymethyl-1-(diethoxyphosphoryl)cyclopropanecarboxylic acid was determined by the single crystal X-ray structure analysis.
Direct formation of cyclic sulfates utilising hypervalent iodine species and sulfur trioxide adducts
作者:Richard I. Robinson、Simon Woodward
DOI:10.1016/s0040-4039(03)00039-x
日期:2003.2
PhIO reacts with SO3·DMF at 0°C to form an active sulfating reagent; subsequent addition of alkenes results in the direct formation of cyclic sulfates in moderate to good yield (35–75%). Terminal, 1,1-disubstituted and cyclopentenes participate in the reaction which is technically very straightforward to carry out.
Trimethylsilylsulfonyl chloride as a source of sulfur trioxide: a novel synthesis of sultones
作者:Alan R. Bassindale、Ibrahim Katampe、Maria G. Maesano、Pravin Patel、Peter G. Taylor
DOI:10.1016/s0040-4039(99)01450-1
日期:1999.10
The reaction of trimethylsilylsulfonyl chloride with iodosobenzene at −78°C generates sulfurtrioxide, or a sulfurtrioxide precursor that reacts with alkenes to give sultones in good yield. This provides a simple method of preparing sulfurtrioxide in situ and avoids the presence of Lewis bases.