An effective, catalytic method has been developed to remove TBS and THP groups from protected alcohols. TBS and THP ethers were selectively cleaved using a catalytic amount of NO+BF4- (5 mol%) in methanol at room temperature.
Efficient nitrosonium （NO＋）-initiated aza-Diels-Alder reactions of N-arylimines with 2,3-dihydrofuran or 3,4-dihydro-2H-pyran allowed access to furano[3,2-c]- or pyrano[3,2-c]quinolines. A mixture of cis and trans-quinoline isomers was obtained in various ratios and yields.
