Guanidine–Copper Complex Catalyzed Allylic Borylation for the Enantioconvergent Synthesis of Tertiary Cyclic Allylboronates

Ge, Yicen; Cui, Xi-Yang; Tan, Siu Min; Jiang, Huan; Ren, Jingyun; Lee, Nick; Lee, Richmond; Tan, Choon‐Hong

doi:10.1002/anie.201813490

Cited by 49 publications

(23 citation statements)

References 100 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A search of the Cambridge Structural Database (Version 2.0.5, last update March 2020) does not reveal any similar phosphine structures. Crystal parameters of closely related protonated Imidazole ligands [7] are similar to the reported crystal structure in this study.…”

Section: Resultssupporting

confidence: 83%

Synthesis, Structure and Hirshfeld Surface Analysis of Phosphine–Imidazolium Salt

Smarun

Jevtović

Ganguly

2020

Molbank

View full text Add to dashboard Cite

In the field of homogeneous catalysis, particularly in anti-Markovnikov hydration, sterically demanding phosphine ligand has found to be very effective. Here we report the crystal structure of a phosphine-imidazolium salt which crystallized in monoclinic space group P21/c with a = 16.6623(13) (Å), b = 10.6686(8) (Å) and c = 12.8916(11) with = 110.232(2). Hirshfeld surface analysis show that the halogen–hydrogen interaction leads to a formation of 1D chain.

show abstract

Section: Resultssupporting

confidence: 83%

Synthesis, Structure and Hirshfeld Surface Analysis of Phosphine–Imidazolium Salt

Smarun

Jevtović

Ganguly

2020

Molbank

View full text Add to dashboard Cite

show abstract

“…Column under each compound shows isolated yields, regioselectivity and enantioselectivity (er) in that order. Boronates ( S )- 11p 11 (a 1,2-adduct, formed with ent- L4a as the ligand) and ( R )- 12p 22 (formed with L5d as the ligand), have been reported before. See Supporting Information for details.…”

Section: Figurementioning

confidence: 77%

Cationic Co(I)-Intermediates for Hydrofunctionalization Reactions: Regio- and Enantioselective Cobalt-Catalyzed 1,2-Hydroboration of 1,3-Dienes

et al. 2019

View full text Add to dashboard Cite

Much of the recent work on catalytic hydroboration of alkenes has focused on simple alkenes and styrene derivatives with few examples of reactions of 1,3-dienes, which have been reported to undergo mostly 1,4-additions to give allylic boronates. We find that reduced cobalt catalysts generated from 1,n-bis-diphenylphosphinoalkane complexes [Ph 2 P-(CH 2) n-PPh 2 ]CoX 2 ; n = 1~5) or from (2-oxazolinyl)phenyldiarylphosphine complexes [(G-PHOX)CoX 2 ] effect selective 1,2-, 1,4-, or 4,3-additions of pinacolborane (HBPin) to a variety of 1,3-dienes depending on the ligands chosen. Conditions have been found to optimize the 1,2-additions. The reactive catalysts can be generated from the cobalt (II)-complexes using trimethylaluminum, methyl aluminoxane or activated zinc in the presence of sodium tetrakis[(3,5-trifluoromethyl)phenyl]borate (NaBARF). The complex, (dppp)CoCl 2 , gives the best results (ratio of 1,2-to 1,4-addition >95:5) for a variety of linear terminal 1,3-dienes and 2-substituted 1,3-dienes. The [(PHOX)CoX 2 ] (X = Cl, Br) complexes give mostly 1,4-addition with linear unsubstituted 1,3-dienes, but, surprisingly selective 1,2-additions with 2-substituted or 2,3-disubstituted 1,3-dienes. Isolated and fully characterized (X-ray crystallography) Co(I)-complexes, (dppp) 3 Co 2 Cl 2 and [(S,S)-BDPP] 3 Co 2 Cl 2 , do not catalyze the reaction unless activated by a Lewis acid or NaBARF, suggesting a key role for a cationic Co(I) species in the catalytic cycle. Regio-and enantioselective 1,2-hydroborations of 2substituted 1,3-dienes are best accomplished using a catalyst prepared via activation of a chiral phosphinooxazoline-cobalt(II) complex with zinc and NaBARF. A number of common functional groups, among them,-OBn,-OTBS,-OTs, N-phthalimidogroups, are tolerated and er's >95:5

show abstract

“… 74 , 76 Aside from these enantioselective transformations, enantioconvergent variants employing either racemic or enantioenriched cyclic allylic electrophiles have also been achieved ( Scheme 3 c). 79 − 81 …”

Section: Allylic Substitution Reactionsmentioning

confidence: 99%

Beyond Carbon: Enantioselective and Enantiospecific Reactions with Catalytically Generated Boryl- and Silylcopper Intermediates

Xue

Oestreich

2020

ACS Cent. Sci.

View full text Add to dashboard Cite

Catalytic asymmetric C–C bond formation with alkylcopper intermediates as carbon nucleophiles is now textbook chemistry. Related chemistry with boron and silicon nucleophiles where the boryl- and accordingly silylcopper intermediates are catalytically regenerated from bench-stable pronucleophiles had been underdeveloped for years or did not even exist until recently. Over the past decade, asymmetric copper catalysis employing those main-group elements as nucleophiles rapidly transformed into a huge field in its own right with an impressive breadth of enantioselective C–B and C–Si bond-forming reactions, respectively. Its current state of the art does not have to shy away from comparison with that of boron’s and silicon’s common neighbor in the periodic table, carbon. This Outlook is not meant to be a detailed summary of those manifold advances. It rather aims at providing a brief conceptual summary of what forms the basis of the latest exciting progress, especially in the area of three-component reactions and cross-coupling reactions.

show abstract

Guanidine–Copper Complex Catalyzed Allylic Borylation for the Enantioconvergent Synthesis of Tertiary Cyclic Allylboronates

Cited by 49 publications

References 100 publications

Synthesis, Structure and Hirshfeld Surface Analysis of Phosphine–Imidazolium Salt

Synthesis, Structure and Hirshfeld Surface Analysis of Phosphine–Imidazolium Salt

Cationic Co(I)-Intermediates for Hydrofunctionalization Reactions: Regio- and Enantioselective Cobalt-Catalyzed 1,2-Hydroboration of 1,3-Dienes

Beyond Carbon: Enantioselective and Enantiospecific Reactions with Catalytically Generated Boryl- and Silylcopper Intermediates

Contact Info

Product

Resources

About