scholarly journals Stereoselective construction of sterically hindered oxaspirocycles via chiral bidentate directing group-mediated C(sp3)–O bond formation

2018 ◽  
Vol 9 (6) ◽  
pp. 1473-1480 ◽  
Author(s):  
Yechan Kim ◽  
Seoung-Tae Kim ◽  
Dahye Kang ◽  
Te-ik Sohn ◽  
Eunyoung Jang ◽  
...  
Keyword(s):  
Bond Formation ◽  
Directing Group ◽  
Sterically Hindered

A new, bidentate, chiral directing group derived from 2,2-dimethyl-1-(pyridin-2-yl)propan-1-amine was discovered, which enables stereoselective palladium(ii)-catalyzed intramolecular C(sp3)–O bond formation.

Imine as a Linchpin Approach for Distal C(sp2)–H Functionalization

2020 ◽  
Author(s):  
Sukdev Bag ◽  
Sadhan Jana ◽  
Sukumar Pradhan ◽  
Suman Bhowmick ◽  
Nupur Goswami ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Bond Activation ◽  
Bond Formation ◽  
Ancillary Ligand ◽  
Significant Challenge ◽  
Site Selectivity ◽  
Directing Group ◽  
Covalently Linked ◽  
Complex Organic ◽  
Post Functionalization

<p>Despite the widespread applications of C–H functionalization, controlling site selectivity remains a significant challenge. Covalently attached directing group (DG) served as an ancillary ligand to ensure proximal <i>ortho</i>-, distal <i>meta</i>- and <i>para</i>-C-H functionalization over the last two decades. These covalently linked DGs necessitate two extra steps for a single C–H functionalization: introduction of DG prior to C–H activation and removal of DG post-functionalization. We introduce here a transient directing group for distal C(<i>sp<sup>2</sup></i>)-H functionalization <i>via</i> reversible imine formation. By overruling facile proximal C-H bond activation by imine-<i>N</i> atom, a suitably designed pyrimidine-based transient directing group (TDG) successfully delivered selective distal C-C bond formation. Application of this transient directing group strategy for streamlining the synthesis of complex organic molecules without any necessary pre-functionalization at the distal position has been explored.</p>

Recent Development in N-Auxilixary-Assisted Intramolecular Amination for Amine Substrates

Synlett ◽  
2015 ◽  
Vol 26 (08) ◽  
pp. 997-1002 ◽  
Author(s):  
Yingsheng Zhao ◽  
Chao Wang ◽  
Jian Han
Keyword(s):  
Transition Metal ◽  
Heterocyclic Compounds ◽  
Bond Formation ◽  
Direct Coupling ◽  
Significant Progress ◽  
Palladium Catalyzed ◽  
Directing Group

Direct coupling of N–H with C–H has aroused great attention in the last decades; during which the directing-group-assisted intramolecular C–N bond formation via transition metal has been achieved significant progress. Herein, we highlight the recent development in the directing-group-assisted intramolecular amination for amine substrates to build the important N-containing heterocyclic compounds.1 Introduction2 Triflamide-Promoted Intramolecular Amination3 Picolinamide-Assisted Intramolecular Amination4 Palladium-Catalyzed Intramolecular Amination under Assistance of Oxalyl Amide5 Conclusion

Early transition metal-catalyzed C–H alkylation: hydroaminoalkylation for Csp3–Csp3 bond formation in the synthesis of selectively substituted amines

2018 ◽  
Vol 54 (89) ◽  
pp. 12543-12560 ◽  
Author(s):  
P. M. Edwards ◽  
L. L. Schafer
Keyword(s):  
Transition Metal ◽  
Bond Formation ◽  
Protecting Group ◽  
Early Transition Metal ◽  
Directing Group ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed ◽  
Early Transition

Protecting group, directing group, and external oxidant free synthesis of structurally diverse amines.

A simple and greener approach for the amide bond formation employing FeCl3 as a catalyst

2015 ◽  
Vol 39 (10) ◽  
pp. 7746-7749 ◽  
Author(s):  
Basavaprabhu Basavaprabhu ◽  
Krishnamurthy Muniyappa ◽  
Nageswara Rao Panguluri ◽  
Panduranga Veladi ◽  
Vommina V. Sureshbabu
Keyword(s):  
Amino Acids ◽  
Bond Formation ◽  
Amide Bond ◽  
Bromoacetic Acid ◽  
Amide Bond Formation ◽  
Glacial Acoh ◽  
Sterically Hindered

A protocol employing FeCl3 in the presence of glacial AcOH is described for the less nucleophilic aniline and its variants, bromoacetic acid and sterically hindered amino acids.

Imine as a Linchpin Approach for Distal C(sp2)–H Functionalization

2020 ◽  
Author(s):  
Sukdev Bag ◽  
Sadhan Jana ◽  
Sukumar Pradhan ◽  
Suman Bhowmick ◽  
Nupur Goswami ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Bond Activation ◽  
Bond Formation ◽  
Ancillary Ligand ◽  
Significant Challenge ◽  
Site Selectivity ◽  
Directing Group ◽  
Covalently Linked ◽  
Complex Organic ◽  
Post Functionalization

<p>Despite the widespread applications of C–H functionalization, controlling site selectivity remains a significant challenge. Covalently attached directing group (DG) served as an ancillary ligand to ensure proximal <i>ortho</i>-, distal <i>meta</i>- and <i>para</i>-C-H functionalization over the last two decades. These covalently linked DGs necessitate two extra steps for a single C–H functionalization: introduction of DG prior to C–H activation and removal of DG post-functionalization. We introduce here a transient directing group for distal C(<i>sp<sup>2</sup></i>)-H functionalization <i>via</i> reversible imine formation. By overruling facile proximal C-H bond activation by imine-<i>N</i> atom, a suitably designed pyrimidine-based transient directing group (TDG) successfully delivered selective distal C-C bond formation. Application of this transient directing group strategy for streamlining the synthesis of complex organic molecules without any necessary pre-functionalization at the distal position has been explored.</p>

scholarly journals Imine as a linchpin approach for meta-C–H functionalization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sukdev Bag ◽  
Sadhan Jana ◽  
Sukumar Pradhan ◽  
Suman Bhowmick ◽  
Nupur Goswami ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Bond Activation ◽  
Bond Formation ◽  
Ancillary Ligands ◽  
Significant Challenge ◽  
Site Selectivity ◽  
Directing Group ◽  
Covalently Linked ◽  
Complex Organic ◽  
Post Functionalization

AbstractDespite the widespread applications of C–H functionalization, controlling site selectivity remains a significant challenge. Covalently attached directing groups (DGs) served as ancillary ligands to ensure ortho-, meta- and para-C–H functionalization over the last two decades. These covalently linked DGs necessitate two extra steps for a single C–H functionalization: introduction of DG prior to C–H activation and removal of DG post-functionalization. Here we report a temporary directing group (TDG) for meta-C–H functionalization via reversible imine formation. By overruling facile ortho-C–H bond activation by imine-N atom, a suitably designed pyrimidine-based TDG successfully delivered selective meta-C–C bond formation. Application of this temporary directing group strategy for streamlining the synthesis of complex organic molecules without any necessary pre-functionalization at the meta position has been explored.

scholarly journals Organocopper cross-coupling reaction for C–C bond formation on highly sterically hindered structures

2019 ◽  
Vol 10 (24) ◽  
pp. 6107-6112 ◽  
Author(s):  
Miku Oi ◽  
Ryo Takita ◽  
Junichiro Kanazawa ◽  
Atsuya Muranaka ◽  
Chao Wang ◽  
...  
Keyword(s):  
Bond Formation ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Carbon Bond ◽  
Carbon Carbon Bond ◽  
Cross Coupling Reaction ◽  
Sterically Hindered

A potent cross-coupling methodology that enables efficient carbon–carbon bond formation at sterically hindered sp2- and sp3-carbons has been developed.

Cu(II)-Catalyzed C–N, C–O, C–Cl, C–S, and C–Se Bond Formation via C(sp2)–H Activation Using 7-Azaindole as an Intrinsic Directing Group

2021 ◽  
Author(s):  
Mohit Kumar ◽  
Raziullah ◽  
Ashfaq Ahmad ◽  
Himangsu Sekhar Dutta ◽  
Afsar Ali Khan ◽  
...  
Keyword(s):  
Bond Formation ◽  
Directing Group
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