nitroalkanes and elemental sulfur with oxiranes was developed with the aid of silver salt. This reaction procedure provides a novel and practical strategy for the rapid assembly of 1,3-oxathiolane skeletons. The reaction exhibited remarkable functional group tolerability and regio-selectivity so that only one regio-isomer formed during the ring opening of oxiranes. Graphical abstract
An efficient procedure for the synthesis of functionalized 3,4-dihydro-2H-pyrans via catalytic multicomponent reaction
作者:Alireza Samzadeh-Kermani、Sajjad Ataeifar
DOI:10.1007/s00706-017-2065-y
日期:2018.1
with reactive nitrilium ion derived from the reaction of isocyanides and oxiranes in the presence of lithium salts in PEG-400. The reaction was successfully utilized to synthesize 3,4-dihydro-2H-pyrans in accordance with a simple and environmentally benign procedure. The optimized reaction conditions allowed the selective synthesis of the highly functionalized 3,4-dihydro-2H-pyrans from the commercially
oxiranes, and malonitrile has been described. In this transformation, copper acetylide was attacked on oxiranes to form homopropargyl alkoxy‐copper intermediate that was further transferred to 2H‐pyrane skeletons by reaction with malonitrile. We found that the reaction was not productive without hexafluoroisopropanol.
[EN] SYSTEMS AND METHODS FOR REGIOSELECTIVE CARBONYLATION OF 2,2-DISUBSTITUTED EPOXIDES<br/>[FR] SYSTÈMES ET PROCÉDÉS DE CARBONYLATION RÉGIOSÉLECTIVE D'ÉPOXYDES 2,2-DISUBSTITUÉS
申请人:UNIV CORNELL
公开号:WO2020102816A1
公开(公告)日:2020-05-22
Provided are methods of carbonylating cyclic substrates to produce carbonyl ated cyclic products. The cyclic substrates may be 2, 2-di substituted epoxides and the cyclic products may be β,β-di substituted lactones. The method may be carried out by forming and pressurizing a reaction mixture of the cyclic substrate, a solvent, carbon monoxide, and a [LA+][CO(CO)4-] catalyst, where [LA+] is a Lewis acid capable of coordinating to the cyclic substrate. The method may proceed with a regioselectivity of 90:10 or greater. The resulting carbonylated cyclic products may be converted to ketone aldol products that retain the stereochemistry and enantiomeric ratio of the carbonyl ated cyclic products.
Isocyanide-based multicomponent reaction for the formation of 1,3-oxathiolane-2-imine derivatives
作者:Alireza Samzadeh-Kermani、Samira Zamenraz
DOI:10.1007/s00706-017-1939-3
日期:2017.10
AbstractThe adduct of isocyanide and elemental sulfur has been employed as the isothiocyanate source in reaction with oxirane to form 1,3-oxathiolane-2-imine derivatives. The optimum conditions are developed using HMPA at 55 °C for 12 h. Various isocyanides and oxiranes were tolerated under the optimum conditions. Graphical abstract