Charge transfer complex enabled photoreduction of ether phosphonium salts for the selective oxyalkylation of enamides

A charge transfer complex(CTC)-enabled photoreduction of ether phosphonium salts for the generation of oxyalkyl radicals was described.The photoreduction provides a convenient method to achieve selective oxyalkylation of enamides with broad substrate scope.The method features operational simplicity,mild and inherent green conditions.

Access to multi-functionalized oxazolines via silver-catalyzed heteroannulation of enamides with sulfoxonium ylides

Disclosed herein is an efficient Ag-catalyzed 4+1 heteroannulation reaction of enamides withα-carbonyl sulfoxonium ylides.The diastereoselective transformation provides a practical access to a diverse range of multi-functionalized oxazoline derivatives.The synthetic utility of the resultant tetrasubstituted oxazolines is further demonstrated by a series of useful manipulations into valuable building blocks of pharmaceutical relevance.

Copper-Catalyzed Direct Oxyphosphorylation of Enamides with P（O）-H Compounds and Dioxygen

A simple and convenient copper-catalyzed direct oxyphosphorylation of enamides with P（O）-H compounds and dioxygen has been developed under mild conditions. This methodology can allow the synthesis of a series of valuable β-ketophosphine oxides β-ketophosphonates in moderate to good yields with a broad substrate scope simply by using readily-available starting materials.

Enantioselective Rh-Catalyzed Hydrogenation of N-Acyl Dehydroamino Esters and Enamides with Monodentate Phosphoramidite Ligands

Chiral monodentate phosphoramidite ligands were conveniently prepared from 1,1＇-bi-2-naphthol （BINOL） and （S）-pyrrolidine in good yields, which were effective chiral ligands in the enantioselective rhodium-catalyzed hydrogenation of dehydroamino esters and enamides at low hydrogenation pressure. High conversion rate （up to 99% for dehydroamino esters and enamides） and good enantioselectivity （up to 96.3% ee for dehy- droamino esters and 91.7% ee for enamides） were obtained.

Asymmetric Spirocyclization Enabled by Iridium and Brønsted Acid-Catalyzed Formal Reductive Cycloaddition

A catalytic,enantioselective spirocyclization of formanilides or formylindolines and enamides has been developed herein.The reaction proceeds through a sequential iridium-catalyzed hydrosilylation of tertiary formanilides and a chiral phosphoric acid-catalyzed formal cycloaddition of exocyclic enamides,thus providing straightforward access to a diverse array of enantioenriched azaspirocycles under mild conditions.

Et2Zn-promoted β-trans-selective hydroboration of ynamide

The trans-hydroboration of alkyne represents a challenging task in organic synthesis.Reported herein is an Et2 Zn promotedβ-trans hydroboration of ynamides by using N-heterocyclic carbene(NHC)-ligated borane as boryl source.The reaction leads to a stereoselective construction of enamides bearing a valuable boryl substituent.Both aromatic and aliphatic ynamides were applicable to the reaction.Synthetic transformation of the C-B bond in the product via Suzuki-Miyaura coupling provides a simple and stereospecific route to multi-substituted enamides.Mechanistic studies were conducted and the possible mechanism was discussed.