Rh(i)-catalyzed dimerization of ene-vinylidenecyclopropanes for the construction of spiro[4,5]decanes and mechanistic studies

Abstract

The Rh(I) complex catalyzed the dimerization of ene-vinylidenecyclopropanes took place smoothly to construct a series of products containing spiro[4,5]decane skeletons featuring simple operation procedure, mild reaction conditions, and good functional...

Iodine radical mediated cascade [3 + 2] carbocyclization of ene-vinylidenecyclopropanes with thiols and selenols via photoredox catalysis

“…We previously investigated a series of cyclization reactions of ene-vinylidenecyclopropanes (ene-VDCPs) 9 with radical-based reagents under different conditions, providing a variety of nitrogen-containing heterocycles. 9 e In view of the aforementioned research circumstances, we wish to report in this paper a novel iodine radical mediated cascade [3 + 2] carbocyclization of ene-vinylidenecyclopropanes via photoredox catalysis upon visible light irradiation, delivering sulfur- or selenium-containing polycyclic derivatives under mild conditions (Scheme 1d).…”

Construction of pyrroles, furans and thiophenes via intramolecular cascade desulfonylative/dehydrogenative cyclization of vinylidenecyclopropanes induced by NXS (X = I or Br)

“…In view of the aforementioned research circumstances, we attempted to introduce heteroatoms into vinylidenecyclopropanes (VDCPs) 10 and assumed that these heteroatomic VDCPs could be excellent candidates for exploiting new methods in cyclization for the rapid construction of heteroaromatics due to their multiple reaction sites. Herein, we describe an intramolecular desulfonylative/dehydrogenative cyclization reaction that proceeds effectively under mild and metal-free conditions, providing functionalized pyrroles, furans, and thiophenes in good yields ( Scheme 1c ).…”

Construction of Spiro[4.5]decanes via Annulations of Azadienes with Nazarov Reagent and DFT Studies

“…For example, the Lewis acid promoted Nazarov cyclization of α‐(trimethyl‐silylmethyl)divinyl ketone provided the spiro[4.5]decane skeleton (Scheme 1a) [9] . Shi and co‐workers reported a Rh(I)‐catalyzed dimerization of enevinylidenecyclopro‐ panes to give spiro[4.5]decanes (Scheme 1b) [10] . In fact, the construction of such a spiro quaternary carbon stereocenter has been a long‐term challenge in organic synthesis, because it had to overcome the strong steric hindrance and high ring strain, especially under mild conditions [11] .…”

“…[9] Shi and co-workers reported a Rh(I)-catalyzed dimerization of enevinylidenecyclopro-panes to give spiro [4.5]decanes (Scheme 1b). [10] In fact, the construction of such a spiro quaternary carbon stereocenter has been a long-term challenge in organic synthesis, because it had to overcome the strong steric hindrance and high ring strain, especially under mild conditions. [11] As a result, it is necessary to develop a novel and mild strategy for the preparation of spiro [4.5]decanes.…”