Enantioselective substrate directed Heck reactions are desirable for the stereoselective synthesis of complex molecules. However, due to the coordination requirements of both chiral ligands and directing groups, such methodologies are underdeveloped. We report herein the desymmetrization of
The first two highly enantioselective palladium‐catalyzed allylic alkylations with benzylic nucleophiles, activated with Cr(CO)3, have been developed. These methods enable the enantioselective synthesis of α‐2‐propenyl benzyl motifs, which are important scaffolds in natural products and pharmaceuticals. A variety of cyclic and acyclic allylic carbonates are competent electrophilic partners furnishing the products in excellent enantioselectivity (up to 99 %
- NSF-PAR ID:
- 10236122
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie
- Volume:
- 128
- Issue:
- 7
- ISSN:
- 0044-8249
- Format(s):
- Medium: X Size: p. 2572-2576
- Size(s):
- ["p. 2572-2576"]
- Sponsoring Org:
- National Science Foundation
More Like this
-
Abstract meso (1R ,2S )‐cyclohex‐4‐ene‐1,2‐diol in an enantioselective and substrate directed fashion. The method provides allcis substituted highly functionalized chiral allylic alcohols in a complementary fashion to other Heck protocols.The products were obtained in high enantioselectivities (higher than 95% ee) and moderate to high yields (38–87%). The noncovalent interactions responsible for the directing effect were elucidated through computational examination of relevant minima and transition structures.magnified image -
Abstract The first highly enantioselective, diastereoselective, and regioselective [2,3]‐rearrangement of iodonium ylides has been developed as a general solution to catalytic onium ylide rearrangements. In the presence of a chiral copper catalyst, substituted allylic iodides couple with α‐diazoesters to generate metal‐coordinated iodonium ylides, which undergo [2,3]‐rearrangements with high selectivities (up to >95:5 r.r., up to >95:5 d.r., and up to 97 %
ee ). The enantioenriched iodoester products can be converted stereospecifically into a variety of onium ylide rearrangement products, as well as compounds that are not accessible by classical onium ylide rearrangements. -
Abstract A protocol for palladium‐catalyzed dearomative functionalization of simple, nonactivated arenes with Grignard reagents has been established. This one‐pot method features a visible‐light‐mediated [4+2] cycloaddition between an arene and an arenophile, and subsequent palladium‐catalyzed allylic substitution of the resulting cycloadduct with a Grignard reagent. A variety of arenes and Grignard reagents can participate in this process, forming carboaminated products with exclusive
syn ‐1,4‐selectivity. Moreover, the dearomatized products are amenable to further elaborations, providing functionalized alicyclic motifs and pharmacophores. For example, naphthalene was converted into sertraline, one of the most prescribed antidepressants, in only four operations. Finally, this process could also be conducted in an enantioselective fashion, as demonstrated with the desymmetrization of naphthalene. -
Abstract A protocol for palladium‐catalyzed dearomative functionalization of simple, nonactivated arenes with Grignard reagents has been established. This one‐pot method features a visible‐light‐mediated [4+2] cycloaddition between an arene and an arenophile, and subsequent palladium‐catalyzed allylic substitution of the resulting cycloadduct with a Grignard reagent. A variety of arenes and Grignard reagents can participate in this process, forming carboaminated products with exclusive
syn ‐1,4‐selectivity. Moreover, the dearomatized products are amenable to further elaborations, providing functionalized alicyclic motifs and pharmacophores. For example, naphthalene was converted into sertraline, one of the most prescribed antidepressants, in only four operations. Finally, this process could also be conducted in an enantioselective fashion, as demonstrated with the desymmetrization of naphthalene. -
Abstract Allylboron reagents are popular in synthesis owing to their versatility and the predictable stereochemical outcomes of their reactions with carbonyl compounds. Herein, we describe the synthesis of (
Z ,Z )‐hexadienyl bis‐boronate1 , a configurationally stable, crystalline, and easy to handle compound, which represents a class of bis‐allylic boron reagents with heretofore untapped synthetic potential. In combination with a chiral phosphoric acid catalyst, the reagent can be employed for the enantioselective allyl transfer reaction to a variety of one‐pot transformations, enabling swift access to functionalized 1,n ‐diols. The in situ conversion of the reagent into the corresponding bis‐borinic ester allows for the direct and diastereoselective two‐fold allyl transfer to aldehydes. This affordsC 2‐ orCi ‐symmetric stereotetrads containing a 1,4‐diol moiety for natural product synthesis. The usefulness of our method was demonstrated with a short synthesis of the lignan (±)‐neo‐olivil.