First Practical and Efficient Synthesis of 3‐Phosphorylated β‐Carboline Derivatives Using the Pictet–Spengler Reaction

Abstract

AbstractWe report here the first practical and efficient synthesis of the diethyl 1,2,3,4‐tetrahydro‐β‐carboline‐3‐phosphonates 3 and 4 as well as diethyl 9H‐β‐carboline‐3‐phosphonates 5 and 6. The target compounds were prepared in good yields by application of the Pictet–Spengler reaction of easily obtainable phosphotryptophan diethyl ester 7. The procedure is based on simple preparation of racemic 7 followed by a Pictet–Spengler reaction with several aldehydes and subsequent oxidation chemistry.