Succinct Syntheses of Methopholine, (±)-Homolaudanosine, and (±)-Dysoxyline via Metal-free One-Pot Double Alkylation on 1-Methyl-3,4-dihydroisoquinolines: Double Addition

A mild one-pot and metal-free condition was discovered to implement two different alkyl groups chemoselectively on 1-methyl-3,4-dihydroisoquinoline (1-Me-DHIQ), one at the nitrogen another at the C1-methyl group. This chemistry is compatible with various DHIQs as well as alkyl halides. Application of this chemistry facilitated the concise syntheses of methopholine, (+/-)-homolaudanosine, and (+/-)-dysoxyline, requiring only two steps from 6,7-dimethoxy-1-Me-DHIQ.