Peizhong Xie

Phosphine-Catalyzed Domino Reaction: Highly Stereoselective Synthesis of trans-2,3-Dihydrobenzofurans from Salicyl N-Thiophosphinyl Imines and Allylic Carbonates

A novel phosphine-catalyzed domino reaction of salicyl N-thiophosphinyl imines and allylic carbonates was developed. The allylic carbonate, in this reaction, serves as a new kind of 1,1-dipolar synthon. This method offered a powerful approach to the construction of a highly substituted trans-2,3-dihydrobenzofuran skeleton with high diastereoselectivity.

PPh3-catalyzed domino reaction: a facile method for the synthesis of chroman derivatives.

A novel domino reaction catalyzed by triphenylphosphine was developed for synthesis of the highly functionalized chroman derivatives. The first example that the gamma-CH(3) of allenoate undergoes cyclization to form chroman derivates was reported.

Phosphine-Catalyzed [4 + 2] Annulation of γ-Substituent Allenoates: Facile Access to Functionalized Spirocyclic Skeletons

The first phosphine-catalyzed [4 + 2] annulation of γ-substituted allenoates with 2-arylidene-1H-indene-1,3(2H)-diones is disclosed. In the reaction, the γ-substituted allenoate serves as a new type of 1,4-dipolar synthon; this broadens the application of γ-substituted allenoates. This method also offers a powerful approach to the construction of highly substituted spiro[4.5]dec-6-ene skeletons in excellent yields, and with complete regioselectivity and high diastereoselectivity.

Substrate-Controlled, Phosphine-Catalyzed Domino Reactions of Activated Conjugated Dienes: Highly Diastereoselective Synthesis of Bicyclic Skeletons

The introduction of the domino reaction as a concept in organic synthesis has inspired fruitful discoveries. A successful domino reaction depends on the selection of efficient catalysts and appropriate substrates. Our group is focused on the study of phosphine-catalyzed domino reactions based on the Morita– Baylis–Hillman (MBH) reaction and the Rauhut–Currier (RC) reaction. The phosphine-catalyzed dimerization of activated alkenes, discovered by Rauhut and Currier in 1963 and coined as Rauhut– Currier (RC) reaction by Krische, is a unique method that creates a new C C bond between the a position of an activated alkene and the b position of a second alkene. To date, considerable efforts have been directed toward the intermolecular RC reactions of simple activated alkenes and the intramolecular versions of tethered bis ACHTUNGTRENNUNG(enones).[4,7] However, domino reactions based on the RC reaction are quite limited. Two fundamental impediments have hampered the incorporation of RC reactions into domino processes. Firstly, the selectivity of cross RC coupling is poor. Moreover, the zwitterionic intermediate A can transfer to B (Scheme 1), which will readily undergo b elimination to terminate the catalytic cycle if it is not compatible with another component and hence make the further domino process impossible. In response to these two challenges, we envisioned that an activated conjugated diene might eliminate these drawbacks. The zwitterionic intermediate A’, through resonance, can exist as B’, a classical intermediate, or as B’’, a phosphorous ylide. The latter can be stabilized by an appendant enone (or enoate) and therefore has potential to trigger subsequent chemical reactions with appropriate substrates. Polycyclic dihydrofuran skeletons are widespread among various natural products of important biological activities and also serve as very useful precursors for the construction of molecular complexity such as ( )-himandrine and cyathin A3. [12] At present, however, the formation of the bicyclic dihydrofuran framework generally involves building a second fiveor six-membered ring onto a preformed dihydrofuran moiety in several steps, which dramatically weakens the overall efficiency. Cyclopentenyl phosphoranes may serve as ligands in the synthesis of many inorganic and organic complexes. To the best of our knowledge, no efficient strategy for the synthesis of bicyclic phosphoranes has been reported because the unusual stability of cyclopentenyl phosphoranes makes the traditional stepwise manipulations rather difficult. To solve these problems, we focused on the appropriate domino processes. [a] J. Ma, Dr. P. Xie, C. Hu, Prof. Dr. Y. Huang, Prof. Dr. R. Chen State Key Laboratory and Institute of Elemento-organic Chemistry Nankai University Tianjin 300071 (P.R. China) Fax: (+86) 22-23503627 E-mail : hyou@nankai.edu.cn Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/chem.201100881. Scheme 1. General concept. RC=Rauhut–Currier.

Phosphine‐Mediated Domino Benzannulation Strategy for the Construction of Highly Functionalized Multiaryl Skeletons

A skeleton crew: A phosphine-mediated domino benzannulation strategy was developed for the synthesis of multiaryl skeletons (see scheme). A wide range of aromatic compounds and functional groups can be assembled into a multiaryl molecule through a core domino process.

Domino Reaction for the Chemo- and Stereoselective Synthesis of trans-2,3-Dihydrobenzofurans from N-Thiophosphinyl Imines and Sulfur Ylides

A novel domino annulation between sulfur ylides and salicyl N-thiophosphinyl imines was developed. The method allows the synthesis of a highly substituted trans-2,3-dihydrobenzofuran skeleton with high yield and excellent chemo- and stereoselectivity.

Phosphine‐Initiated Domino Reaction: A Convenient Method for the Preparation of Spirocyclopentanones

An efficient synthetic approach has been developed for the construction of the spirocyclopentanone skeleton via a phosphine-catalyzed [3+2] annulation reaction. With this novel and economical protocol, various quaternary carbon-centered spirocyclopentanones could be readily obtained.

Tuning catalysts to tune the products: phosphine-catalyzed aza-Michael addition reaction of hydrazones with allenoates.

A new tunable phosphine-catalyzed aza-Michael β-addition reaction between allenoates and various hydrazones has been developed. These reactions are most-efficiently promoted by a catalytic amount of phosphine catalysts. These atom-economical reactions are operationally simple and their corresponding adducts can been achieved in high yields and high selectivity under mild reaction conditions. Further studies revealed that different phosphine catalyst can produce different adducts from the same starting materials.

Organocatalytic domino reaction of salicyl N-thiophosphoryl imines and methyl vinyl ketone initiated by an aza-MBH reaction with bifunctional phosphine catalysts

We report two domino reactions between salicyl N-thiophosphoryl imines and methyl vinyl ketone catalyzed by bifunctional phosphine catalysts and DBU. These reactions provide two simple and efficient methods to construct chromans and chromens under mild conditions, respectively.