S S symmetry Review EnantioselectiveReview Catalytic Synthesis ofEnantioselectiveN-alkylated Indoles Catalytic Synthesis of DmitriN-alkylated Trubitsõn and Indoles Tõnis Kanger * DepartmentDmitri Trubitsõn of Chemistry and Tõnis and Biotechnology, Kanger * School of Science, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia;
[email protected] * Correspondence:Department of Chemistry
[email protected]; and Biotechnology, Tel.: School+372-620-4371 of Science, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia;
[email protected] Received:* Correspondence: 25 June 2020;
[email protected]; Accepted: 14 July 2020; Tel.: Published: +372-620-4371 17 July 2020 Received: 25 June 2020; Accepted: 14 July 2020; Published: date Abstract: During the past two decades, the interest in new methodologies for the synthesis of chiralAbstract:N-functionalized During the past indoles two decades, has grown the interest rapidly. in The new review methodologies illustrates for ethefficient synthesis applications of chiral of organocatalyticN-functionalized and indoles organometallic has grown strategies rapidly. for The the review construction illustrates of chiral efficientα-N -branchedapplications indoles. of Bothorganocatalytic the direct functionalization and organometallic of strate the indolegies for core the construction and indirect of methods chiral α- basedN-branched on asymmetric indoles. N-alkylationBoth the direct of indolines, functionalization isatins and of the 4,7-dihydroindoles indole core and indirect are discussed. methods based on asymmetric N- alkylation of indolines, isatins and 4,7-dihydroindoles are discussed. Keywords: indole; asymmetric synthesis; organocatalysis; transition-metal catalysis; C-N bond formation;Keywords: enantioselective; indole; asymmetric heterocycles synthesis; organocatalysis; transition-metal catalysis; C-N bond formation; enantioselective; heterocycles 1.