Chiral multifunctional thiourea-phosphine catalyzed asymmetric [3 + 2] annulation of Morita–Baylis–Hillman carbonates with maleimides

Abstract

SummaryWe have developed a multifunctional thiourea-phosphine catalyzed asymmetric [3 + 2] annulation of Morita–Baylis–Hillman (MBH) carbonates with maleimides, which can efficiently construct functionalized cyclopentenes bearing three contiguous stereocenters in moderate to excellent yields and excellent diastereo- and enantioselectivities. A plausible mechanism has been also proposed on the basis of control experiments and previous literature.

Advances in Annulation Reactions Initiated by Phosphorus Ylides Generated in situ

“…By employing the same multifunctional thiourea-phosphane catalyst, Shi and co-workers further expanded the asymmetric [3 + 2] annulation to maleimides, obtaining functionalized cyclopentenes, each containing three contiguous stereocenters, in moderate to excellent yields and with excellent diastereoand enantioselectivity (Scheme 25). [19] Furthermore, the same research group also extended this methodology to 2-arylideneindane-1,3-diones for enantioselective synthesis of spirocyclic cyclopentenes (Scheme 26). [20] Scheme 25.…”

Applications of Chiral Phosphine‐Based Organocatalysts in Catalytic Asymmetric Reactions

“…Subsequently, they applied similar chiral phosphines to achieve the highly enantioselective [3+2] annulation of MBH carbonates with maleimides 21. Shi and co‐workers also developed a series of multifunctional thiourea phosphines derived from natural amino acids and applied them in the asymmetric [3+2] annulation of MBH carbonates with trifluoroethylidenemalonates,22 maleimides,23 and 2‐arylideneindane‐1,3‐diones 24. Liu and co‐workers reported an efficient Me‐DuPhos‐catalyzed asymmetric [3+2] cycloaddition reaction of MBH carbonates of isatins with N ‐phenylmaleimide 25.…”

Asymmetric Reactions Catalyzed by Chiral Tertiary Phosphines

“…Subsequently, they employed other substrates such as maleimides and 2‐arylideneindane‐1,3‐diones, and also achieved highly enantioselective [3+2] cycloaddition reactions, affording the desired functionalized cyclopentenes in good reaction outcomes. [ 54 ] In the catalysis of same multifunctional thiourea‐phosphine 159 , a wide range of maleimides 154 with MBH carbonates underwent this [3+2] cycloaddition reaction smoothly, furnishing a series of functionalized cyclopentenes 155 bearing three contiguous stereocenters in moderate to excellent yields and excellent diastereo‐ and enantioselectivities (Scheme 35, eq. b).…”