Highly Stereoselective 7-Endo-Trig/Ring Contraction Cascade To Construct Pyrrolo[1,2-a]quinoline Derivatives
摘要:
With the cooperation of Cram's phenonium ion, a novel cascade reaction was illustrated to construct pyrrolo[1,2-a]quinolines as a sole diastereoisomer in good to excellent yields. Preliminary mechanistic studies revealed that the gamma-lactam ring and electron-rich arene are important driving forces for ring contraction.
Catalytic Asymmetric Synthesis of the Central Tryptophan Residue of Celogentin C
作者:Steven L. Castle、G. S. C. Srikanth
DOI:10.1021/ol035236x
日期:2003.10.1
[reaction: see text] Chiral phase-transfer catalyst 5 containing an electron-deficient trifluorobenzyl moiety promoted the alkylation of glycine derivative 6 with propargyl bromide 7a in good yield and excellent ee. The resulting propargyl glycine 8 was converted to 14, the central tryptophan residue of Celogentin C, in two steps, with the Pd-catalyzed heteroannulation as the key transformation. This