Efficient Access to Benzochromeno[2,3-d]pyrimidine Derivatives from β-enamino Nitriles by Bis(Trichloromethyl) Carbonate and Triphenylphosphine Oxide

Triphosgene and Triphenylphosphine Oxide-Mediated Cascade Heterocyclization of N-Acylated Anilines: One-Pot Synthesis of 2,4-Dichloroquinolines

A one-pot cascade chlorination/heterocyclization strategy has been developed for the synthesis of 2,4-dichloro-substituted quinolines from acylated anilines using triphosgene and triphenylphosphine oxide. Obviating the conventional harsh conditions of chlorination, synthetic useful quinolines with moderate to good yields were obtained through this reaction. The mechanism study exhibited that the formation of a β-enamine intermediate plays a vital role in the generation of the final product.

A decade review of triphosgene and its applications in organic reactions

This review article highlights selected advances in triphosgene-enabled organic synthetic reactions that were reported in the decade of 2010-2019. Triphosgene is a versatile reagent in organic synthesis. It serves as a convenient substitute for the toxic phosgene gas. Despite its first known preparation in the late 19th interestingly began only three decades ago. Despite the relatively short history, triphosgene has been proven to be very useful in facilitating the preparation of a vast scope of value-added compounds, such as organohalides, acid chlorides, isocyanates, carbonyl addition adducts, heterocycles, among others. Furthermore, applications of triphosgene in complex molecules synthesis, polymer synthesis, and other techniques, such as flow chemistry and solid phase synthesis, have also emerged in the literature.

One-Pot Cascade Heterocyclization of γ- and β-Ketomalononitriles to 2,4-Dichloro-Substituted Pyrano[2,3- d]pyrimidines and Furo[2,3- d]pyrimidines Mediated by Triphosgene and Triphenylphosphine Oxide

A one-pot cascade heterocyclization strategy has been developed for the synthesis of 2,4-dichloro-substituted pyrano[2,3- d]pyrimidines and furo[2,3- d]pyrimidines from linear γ- and β-ketomalononitriles using triphosgene and triphenylphosphine oxide. The reaction afforded synthetic useful products with moderate to good yields, bypassing the conventional harsh conditions of chlorination. The mechanistic study revealed that the reaction proceeded with a non-isocyanate route, and the second step may conduct in a triphenylphosphine oxide-catalyzed manner.