Naphtho cyclopropene cycloaddition

Saito reported the extension of Billups tandem silver-catalyzed ring-opening cycloaddition reaction methodology to addition to imines (Scheme 2.45).77 Naphtho- /) cyclopropene 167 added to substituted aryl imines 168 at room temperature in the... 

Treatment of naphtho[. ]cyclopropene 686 with dimethyltrithiocarbonate and with l,3-dithiole-2-thiones affords l,3-dihydrobenzo[2,3-( ]thiophenes 687 and 688, respectively. This reaction involves a [2Jt+2cr]-type cycloaddition process (Scheme 103) <2004H(62)773>. 

Benzocyclopropene (88) and naphtho[h]cyclopropene react with various alkenic substrates to give cy-cloaddidon piquets in the presence of silver ion. Reaction of (88 equation 39) with butadiene assisted by 1 mol % of AgBp4 in benzene (0 C, 30 min) gives (89) and (90). Dimethylallene (91 equation 40) and oct-4-yne (95 equation 41) also react readily with (88) in the presence of silver ion to give the corresponding cycloaddition products (92), (93) and (96), together with acyclic products (94) and (97). 

---