Jianlin Han

Cu-Catalyzed Deoxygenative C2-Sulfonylation Reaction of Quinoline N-Oxides with Sodium Sulfinate

An unexpected Cu-catalyzed deoxygenative C2-sulfonylation reaction of quinoline N-oxides in the presence of radical initiator K2S2O8 was developed that used sodium sulfinate as a sulfonyl coupling partner. The mechanism studies indicate that the reaction proceeds via Minisci-like radical coupling step to give sulfonylated quinoline with good chemical yields.

Detrifluoroacetylative in Situ Generation of Free 3-Fluoroindolin-2-one-Derived Tertiary Enolates: Design, Synthesis, and Assessment of Reactivity toward Asymmetric Mannich Reactions

The discovery of detrifluoroacetylative in situ generation of a new type of fluorinated amide enolates derived from 3-fluoroindolin-2-one and their asymmetric Mannich additions with sulfinylaldimines bearing fluoroalkyl groups is reported, which afforded α-fluoro-β-(fluoroalkyl)-β-aminoindolin-2-ones containing C-F quaternary stereogenic centers with excellent yields and high diastereoselectivities.

Sunlight-promoted cyclization versus decarboxylation in the reaction of alkynoates with N-iodosuccinimide: easy access to 3-iodocoumarins

A sunlight-initiated radical conversion of aryl alkynoates to 3-iodocoumarins has been achieved using N-iodosuccinimide as the iodine source without the use of a catalyst or additive. Experimental, X-ray analysis, and computational studies indicate that the reaction under sunlight proceeds through iodination, spirocyclization and ring expansion to form the kinetic product. The sunlight-driven reaction provides a green pathway to especially valuable 3-halocoumarins derivatives.

Copper-Catalyzed Aerobic Oxidative Reaction of Sulfonyl Hydrazides with Alcohols: An Easy Access to Sulfinates.

A Cu-catalyzed aerobic oxidative reaction between sulfonyl hydrazides and alcohols has been developed. In this reaction, sulfonyl hydrazides act as the sulfinic acid precursors to react with alcohols, resulting in sulfinic esters with up to 72u2009% yield. This catalytic system tolerates a wide range of sulfonyl hydrazide substrates, and represents a new strategy for the transformation of readily available sulfonyl hydrazides.

Cascade alkylarylation of substituted N-allylbenzamides for the construction of dihydroisoquinolin-1(2H)-ones and isoquinoline-1,3(2H,4H)-diones.

Summary An oxidative reaction for the synthesis of 4-alkyl-substituted dihydroisoquinolin-1(2H)-ones with N-allylbenzamide derivatives as starting materials has been developed. The radical alkylarylation reaction proceeds through a sequence of alkylation and intramolecular cyclization. The substituent on the C–C double bond was found to play a key role for the progress of the reaction to give the expected products with good chemical yields. Additionally, N-methacryloylbenzamides were also suitable substrates for the current reaction and provided the alkyl-substituted isoquinoline-1,3(2H,4H)-diones in good yield.

N-Iodosuccinimide-Initiated Spirocyclopropanation of Styrenes with 1,3-Dicarbonyl Compound for the Synthesis of Spirocyclopropanes.

Herein is reported an N-iodosuccinimide-initiated spirocyclopropanation reaction of styrenes with 1,3-dicarbonyl compounds in the presence of white LED light. The reaction proceeds via two C-H and two C-I bond cleavage event, along with two C-C bond formation event, and formation of quaternary centers. These reactions could be carried out at room temperature and tolerated a wide range of substrates, resulting in good to excellent chemical yields. This developed radical reaction provides easy and practical access to spiro[2.4]heptane-4,7-dione derivatives.