Singh, Kamaljeet; Trinh, Winston; Weaver, Jimmie D. published the artcile< Elusive thermal [2+2] cycloaddition driven by visible light photocatalysis: tapping into strain to access C2-symmetric tricyclic rings>, HPLC of Formula: 370878-69-6, the main research area is thermal cycloaddition visible light photocatalysis strain sym tricyclic ring.
A mild and operationally simple methodol. is reported for the synthesis of cyclobutane rings imbedded within a C2-sym. tricyclic framework. The method uses visible light and an iridium-based photocatalyst to drive the oft-stated “”forbidden”” thermal [2 + 2] cycloaddition of cycloheptenes and analogs. Importantly, it generates cyclobutane with four new stereocenters with excellent stereoselectivity, and perfect regioselectivity. The reaction is propelled forward when the photocatalyst absorbs a visible light photon, which transfers this energy to the cycloheptene. Key to success is, upon excitation to the triplet via sensitization from the photocatalyst, the double bond isomerizes to give the transient, highly strained, trans-cycloheptene. The trans-cycloheptene undergoes a strain relieving thermal, intermol. [π2s + π2a] cycloaddition with another cis-cycloheptene. X-ray anal. reveals that the major product is the head-to-head, C2-sym. all trans-cyclobutane. Addnl., a dramatic display structural complexity enhancement is observed with the use of chiral cycloheptenols possessing one stereocenter, which results in the formation of cyclobutanes with six contiguous stereocenters with good to excellent diastereocontrol, and can be used to isolate single stereoisomers of stereochem. complex cyclobutanes in good yield.
Organic & Biomolecular Chemistry published new progress about Cis-trans isomerization. 370878-69-6 belongs to class pyridine-derivatives, and the molecular formula is C33H21F3IrN3, HPLC of Formula: 370878-69-6.