%0 Generic
%A Han, Chunyu
%C Heidelberg
%D 2022
%F heidok:30611
%R 10.11588/heidok.00030611
%T Gold-Catalyzed C-H Alkynylations with Hypervalent Iodine(III) Reagents
%U https://archiv.ub.uni-heidelberg.de/volltextserver/30611/
%X In Chapter 2, a gold-catalyzed direct alkynylation for the synthesis of 1,3-enynes using  alkyl 3-aminoacrylates and hypervalent iodine reagents is reported. This reaction,  which involves the formation of an alkynyl Au(III) species and a direct C-H activation  of alkyl 3-aminoacrylates, reports twenty-six successful conversions in 62-92% yield  with excellent functional group tolerance. In addition, only one configuration of 1,3-  enynes containing enamines is produced and no further cyclization product is found.  In Chapter 3, a gold-catalyzed cascade C(sp3)-H alkynylation/ oxy-alkynylation of β-  keto compounds with hypervalent iodine(III) reagents for the synthesis of tetrasubstituted  furans is described. The alkynyl Au(III) species plays a crucial role in  Au(I)/Au(III) catalytic cycles. The two operating catalytic cycles include an  alkynylation of activated C(sp3)-H bond and an oxy-alkynylation of an β-alkynyl ketone.  This simple strategy features mild reaction conditions, high functional group tolerance,  and a wide substrate scope. Furthermore, the synthetic utility of the method was  demonstrated by diverse functionalizations of the final products. Gram-scale synthesis  and proposed mechanism are also presented.  In Chapter 4, another gold-catalyzed cascade C(sp3)–H alkynylation/Nitrogenalkynylation  of 2-pyridine compounds with hypervalent iodine(III) reagents for the  synthesis of poly-substituted indolizines is described. The broad substrate scope, good  functional group tolerance and good efficiency render this method useful for organic  synthesis, especially for the synthesis of nitrogen-containing compounds. Gram-scale  synthesis and proposed mechanism are also revealed.