Synthesis Of 2-thiaindolines And 2-oxophosphorindolines Based On Intramolecular Aromatic C-H Insertion

The derivatives of indoles and indolines are biological important compounds and extensively exist in natural products. Compared with diverse synthetic methods for the derivatives of indoles and indolines, only limited methods have been reported for the synthesis of 2-thiaindolines and 2-oxophosphorindolines. It is an efficient and convenient synthesic method based on intramolecular aromatic C-H insertion reaction to construct the indolinone’s structure, which is a member of indoline’s derivatives. Sulfonyl group and phosphonyl group are the sulfur and phosphorus analogues of the carbonyl group as the members of electron-withdrawing substituent family, so the methylene attached to a-electron-withdrawing substituted sulfonamides and phosphonamidates is active enough to transform into diazo compounds in the presence of base and diazo transfer reagents. Diazo compounds are excellent carbene precursors, which can perform C-H insertion reactions in the presence of metal catalyts, under photoirridiation, or at high temperature. The thesis focuses on employing a-electron-withdrawing-group substituted sulfonamides and phosphonamidates as starting materials to develop a synthetic method for 2-thiaindolines and 2-oxophosphorindolines based on intramolecular aromatic C-H insertion.Firstly, a series of 2-thiaindolines with aryl and alkyl at the N atom was selectively synthesized through the control of a-electron-withdrawing substituents. The carbene precursors diazosulfonamides proceed intramolecular aromatic C-H insertion reaction in the presence of catalyst Cu(II), affording products 2-thiaindolines, namely 1,3-dihydrobenzo[c]isothiazole-2,2-dioxides. Only 2-thiaindolines with aryl on the N atom can be obtained when carbethoxy substituted diazosulfonamides were used. The change of a-electron-withdrawing substituent into benzoyl or acetyl realized the preparation of 2-thiaindolines with alkyl on the N atom. The intramolecular chemoselectivity was realized when diazosulfonamides with N-phenylacylamino as a-electron-withdrawing substituent was conducted, only leading to indolinone derivatives without 2-thiaindolines. Secondly, the synthesis of 2-oxophosphorindolines, namely 1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxide, was developed featured with inexpensive catalyst by employing a-electron-withdrawing-group substituted diazophosphonamidates as starting materials.In summary, efficient, easily-handled, practical, and economic method approaching 2-thiaindolines and 2-oxophosphorindolines have been developed via intermediate of diazo compounds.