Rh(?)-Catalyzed C-H Activation Of Olefin And Carbene Insertion

Transition metal catalyzed C-H activation and functionalization provides atom-and step-economical efficient methods for the synthesis of various drug-related chemical intermediates and complex organic compounds.It has been widely applied in pharmaceutical intermediate synthesis,natural product synthesis,and synthesis of polymer compounds.Due to the unique structure and coordination properties of Cp*Rh(?)(Cp*=1,2,3,4,5-pentamethylcyclopenta-1,3-diene)catalysts,the catalytic system is generally highly efficient,good selective,and functional group compatible.The activation of C-H bonds catalyzed by Cp*Rh(?)has gradually gained attention.In this paper,Rh(?)-catalyzed C-H bond activation of olefin and carbene insertion was studied.The results are as following:1).Rh(?)-catalyzed cascade C-H activation of benzoylacetonitriles and annulation with sulfoxonium ylides was realized,leading to selective synthesis of naphthols,2,3-dihydronaphtho[1,8-bc]p-yrans,and naphtho[1,8-bc]pyrans.This stepeconomic reaction proceeded efficiently under mild and redox-neutral conditions via multiple C-H activations.2).Rhodium(?)-catalyzed regio-and chemoselective[5+2]annulation between N-(cyanoacetyl)indolines and sulfoxonium ylides has been realized,leading to efficient construction of seven-membered rings under mild conditions.This reaction proceeded via C–H activation with sulfoxonium ylides as carbene synthons.3).A Rh(?)-catalyzed addition of benzylic C(sp~3)-H bond to?,?-unsaturated ketones/aldehydes has been realized,leading to efficient synthesis of?-aryl ketones/aldehydes.This atom-economic reaction proceeded under mild and redoxneutral conditions with a broad substrate scope.Besides benzylic C-H,allylic C-H bonds are also applicable when assisted by O-methyl ketoxime directing groups.4).Rh(?)-catalyzed[3+2]annulation of cyclic N-sulfonyl or N-acyl ketimines with activated alkenes has been realized,leading to the synthesis of spirocycles with three continuous stereogenic centers.This atom-economic reaction proceeded efficiently under mild and redox-neutral conditions via a C-H activation pathway,and the coupling is diastereodivergent,with the diastereoselectivity being controlled by silver additives.