A Mild and General Larock Indolization Protocol for the Preparation of Unnatural Tryptophans.
A mild and general protocol for the Pd(0)-catalyzed heteroannulation of o-bromoanilines and alkynes is described. Application of a Pd(0)/P((t)Bu)3 catalyst system enables the efficient coupling of o-bromoanilines at 60 °C, mitigating deleterious side reactions and enabling access to a broad range of useful unnatural tryptophans. The utility of this new protocol is demonstrated in the highly convergent total synthesis of the bisindole natural product (-)-aspergilazine A.
The Warren and Katharine Schlinger Laboratory of Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California 91125, United States.
Kangway V
KV
Chuang
The Warren and Katharine Schlinger Laboratory of Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California 91125, United States.
Madeleine E
ME
Kieffer
The Warren and Katharine Schlinger Laboratory of Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California 91125, United States.
Sarah E
SE
Reisman
D004151:Dipeptides / Q000138:chemical synthesis* / Q000737:chemistry; D007211:Indoles / Q000737:chemistry*; D008968:Molecular Conformation; D013237:Stereoisomerism; D014364:Tryptophan / Q000138:chemical synthesis* / Q000737:chemistry
D004151:Dipeptides; D007211:Indoles; C505497:aspergillazine A; D014364:Tryptophan