An electron was found to catalyze the coupling of magnesium diarylamides with aryl iodides giving triarylamines through a radical-anion intermediate. The transformation requires no transition metal catalysts or additives, and a wide array of products are formed in good-to-excellent yields.
View Article and Find Full Text PDFArylzinc reagents, prepared from aryl halides/zinc powder or aryl Grignard reagents/zinc chloride, were found to undergo coupling with aryl and alkenyl halides without the aid of transition-metal catalysis to give biaryls and styrene derivatives, respectively. In this context, we have already reported the corresponding reaction using aryl Grignard reagents instead of arylzinc reagents. Compared with the Grignard cross-coupling, the present reaction features high functional-group tolerance, whereby electrophilic groups such as alkoxycarbonyl and cyano groups are compatible as substituents on both the arylzinc reagents and the aryl halides.
View Article and Find Full Text PDFAllenes are molecules based on three carbons connected by two cumulated carbon-carbon double bonds. Given their axially chiral nature and unique reactivity, substituted allenes have a variety of applications in organic chemistry as key synthetic intermediates and directly as part of biologically active compounds. Although the demands for these motivated many endeavours to make axially chiral, substituted allenes by exercising asymmetric catalysis, the catalytic asymmetric synthesis of fully substituted ones (tetrasubstituted allenes) remained largely an unsolved issue.
View Article and Find Full Text PDFA rhodium-catalyzed asymmetric synthesis of silicon-stereogenic dibenzooxasilines has been developed. High enantioselectivities have been achieved by employing (S,S)-Me-Duphos as the ligand through "enantioselective transmetalation".
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