Synthesis of 5,5,6,6,21,21,22,22-octamethyl-5,6,21,22-tetragerma[10.10]paracyclophane
摘要:
A [10,10]paracyclophane, 5,5,6,6,21,21,22,22-octamethyl-5,6,21,22-tetragerma[10.10]paracyclophane (4a), with two (RRGeGeRR2)-R-1-Ge-2-R-1- moieties in the center of two bridges, was prepared. An attempt to synthesize cyclophanes, 4b (R-1 = Me; R-2 = Ph) and 4c (R-1 = R-2 = Ph) was also made. The products were not analytically pure even after strenuous purification procedure to indicate that a double Wurtz coupling reaction is extremely difficult and necessarily accompanied by formation of polymeric byproducts. (C) 2003 Elsevier B.V. All rights reserved.
Asymmetric Palladium‐Catalyzed Oxycarbonylation of Terminal Alkenes: Efficient Access to β‐Hydroxy Alkylcarboxylic Acids
作者:Bing Tian、Xiang Li、Pinhong Chen、Guosheng Liu
DOI:10.1002/anie.202104252
日期:2021.6.25
leading to high reactivity and excellent enantioselective control. Compared to the conventional methods, the reaction itself features alkenes as easily prepared starting materials, mild and operationally simple reaction conditions, and insensitivities to air and water. Moreover, this method allows for broad alkene substrate scope, excellent regio- and enantioselectivities, scalabilities and a wide array
Radical Addition-Triggered Remote Migratory Isomerization of Unactivated Alkenes to Difluoromethylene-Containing Alkenes Enabled by Bimetallic Catalysis
A fascinating alkeneremote migratory isomerization engendered by carbon radical addition to C═C bond in alkenes via bimetalliccatalysis has been disclosed. A diverse array of alkenes bearing distantly incorporated the difluoromethylene (RCF2R′) functionality have been expediently obtained. The retainment of C═C bonds in products could serve as an useful synthetic platform furnishing otherwise difficult
Dual role of allylsamarium bromide as a Grignard reagent and a single electron transfer reagent in the one-pot synthesis of terminal olefins
作者:Ying Li、Yuan-Yuan Hu、Song-Lin Zhang
DOI:10.1039/c3cc45611k
日期:——
The utility of allylsamarium bromide, both as a nucleophilic reagent and a single-electron transfer reagent, in the reaction of carbonyl compounds with allylsamarium bromide in the presence of diethyl phosphate is reported in this communication. From a synthetic point of view, a simple one-pot method for the preparation of terminal olefins is developed.
A [10,10]paracyclophane, 5,5,6,6,21,21,22,22-octamethyl-5,6,21,22-tetragerma[10.10]paracyclophane (4a), with two (RRGeGeRR2)-R-1-Ge-2-R-1- moieties in the center of two bridges, was prepared. An attempt to synthesize cyclophanes, 4b (R-1 = Me; R-2 = Ph) and 4c (R-1 = R-2 = Ph) was also made. The products were not analytically pure even after strenuous purification procedure to indicate that a double Wurtz coupling reaction is extremely difficult and necessarily accompanied by formation of polymeric byproducts. (C) 2003 Elsevier B.V. All rights reserved.