Rh(i)-Catalyzed intramolecular [3 + 2] cycloaddition reactions of yne-vinylidenecyclopropanes

Abstract

A Rh(i)-catalyzed intramolecular [3 + 2] cycloaddition reaction of yne-vinylidenecyclopropanes has been developed, providing fused [6.5]-bicyclic products in moderate to good yields.

Engaging Yne‐Allenes in Cycloaddition Reactions: Recent Developments

“…The reaction resulted in a series of fused [6.5]‐bicyclic structures 65 in 41%—91% yields (Scheme 20). [ 77 ] Many BsN‐, O‐ and CH 2 ‐anchored yne‐allenes possessing different substituents (R 1 ) such as primary/secondary alkyl, 1‐butenyl and benzyl groups could all tolerate this catalytic system, giving the corresponding products in good yields. Various substituents at the alkynyl moiety of yne‐allenes including alkyl, benzyl, primary or secondary acetoxyalkyl, alkenyl, internal alkynyl, and ester proved to be suitable, producing the targets in good yields ranging from 72% to 91%.…”

Palladium catalyzed stereoselective intramolecular [3 + 2] cycloaddition reactions of (E) & (Z)-ene-vinylidenecyclopropanes

“…The metallocyclohexane species Int-B undergoes reductive elimination to produce the bicyclic products. Recently, several significant examples of [3 + 2] cycloaddition reactions of MCPs and VDCPs using Pd, 8 Rh, 9 Co, 10 and Ni 11 as catalysts have been disclosed.…”

Mechanistic Insights into the Ru(II)-Catalyzed Intramolecular Formal [3 + 2] Cycloaddition of (E)-1,6-Enynes

“…Despite the great achievements with these developed transformations, to the best of our knowledge, the intramolecular [3 + 2] cycloaddition reaction of 1,6-enynes is still challenging (Scheme B). One of the main restrictions lies in the fact that this intramolecular [3 + 2] cycloaddition needs the participation of a saturated C­(sp 3 )–H bond rather than the above-observed participation of the carbon–carbon single/double bonds in the intramolecular [ n + 2] ( n = 2, 4, 5, 6) cycloadditions . This limitation means a compulsory demand via a 1,2-hydrogen shift that must undergo the cleavage of a saturated C­(sp 3 )–H bond.…”