Total synthesis of sinopyrine B

The first total synthesis of sinopyrine B has been concisely achieved in 10 linear steps with a 7% overall yield. Importantly, the crucial pyrrolo[2,1-a]isoquinoline skeleton, widely existing in various natural products and pharmacological molecules, was rapidly constructed in one step through a unique formal [3 + 2] cyclization between 2-(3,4-dihydroisoquinolin-2(1H)-yl)malononitrile 3 and trimethyl silyl acetylene as the key step. [Display omitted] The first total synthesis of sinopyrine B has been concisely achieved in 10 linear steps with a 7 % overall yield. Importantly, the crucial pyrrolo[2,1-a]isoquinoline skeleton, widely existing in various natural products and pharmacological molecules, was rapidly constructed in one step through a unique formal [3 + 2] cyclization between 2-(3,4-dihydroisoquinolin-2(1H)-yl)malononitrile 3 and trimethyl silyl acetylene as the key step.