Kanth Josyula | University of Hyderabad (original) (raw)

Papers by Kanth Josyula

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

ChemInform, Jun 27, 2011

Reinvestigation of Aminomethyltrifluoroborates and Their Application in Suzuki-Miyaura Cross-Coup... more Reinvestigation of Aminomethyltrifluoroborates and Their Application in Suzuki-Miyaura Cross-Coupling Reactions.-Treatment of borate (I) with amines does not yield the corresponding potassium borates but ammoniomethyltrifluoroborates of type (III). The latter smoothly undergo Suzuki-Miyaura cross-coupling with aromatic chlorides as well as bromides to afford aminomethylated arenes in good to high yields. Their transformation into the corresponding potassium borates, however,

ChemInform, Jun 14, 2010

Complexation of tertbutyldialkylamines (I) with BH 3 yields stable, highly reactive liquid adduct... more Complexation of tertbutyldialkylamines (I) with BH 3 yields stable, highly reactive liquid adducts, especially from (Ic), (Id), and (Ig), as borane carriers for hydroboration reactions, which can serve as eco-friendly substitutes for the currently popular hydroborating-reducing agents Me 2 S•BH 3 and THF•BH 3 .-(BROWN, HER

Journal of the Indian Institute of Science, Jan 2, 2013

Reactlorl olh(1.5 mole eq) w x '~ BHI.N(CB+PII (I cq 1 ui benmle at room lcmpmarure gwri R l i N(... more Reactlorl olh(1.5 mole eq) w x '~ BHI.N(CB+PII (I cq 1 ui benmle at room lcmpmarure gwri R l i N(C:H,):Ph reagent The BIi reagent prepaicd In th~a way oil rcact~ou wllh CIICOOH glve5 HI ~1 1~1 1 la !useful for hydroiodinatmn o f alkenes and alkymcs io &tam alhyl 2nd dhcnyl mdidcs In 74 to 84% jields. The BIi reagent 1s also useful for cicavigc o t N~caihnn~ntes to secondary amloz\. Appl~oarion of this rzngent ibr cleavage of ethers, esrers and suiphonnies is also d r c l h e d Key wards: lodoboiiine, alkyl and alhehyl lod~dr synthesis. clra\age of caibarnatc\, ethen. eltsrs and aulphooaies

Synthetic Communications, Feb 1, 1994

N-Benzyl tertiary amines on reaction with ethyl chloroformate give the corresponding debenzylated... more N-Benzyl tertiary amines on reaction with ethyl chloroformate give the corresponding debenzylated N-carbamates which on treatment with I3B:N(C2H5)2Ph complex yield the secondary amines.

Tetrahedron Letters, Jul 1, 1996

Abstract Reaction of low valent titanium reagent, prepared in situ in THF by the reduction of TiC... more Abstract Reaction of low valent titanium reagent, prepared in situ in THF by the reduction of TiCl 4 by Mg powder, with certain imines leads to the formation of imidazolidine derivatives in moderate to good yields.

ChemInform, Aug 4, 2010

Low-Valent Titanium Induced Reductive Coupling of Nitriles with Nitro Compounds.-A new method to ... more Low-Valent Titanium Induced Reductive Coupling of Nitriles with Nitro Compounds.-A new method to obtain amidines (III) and 2-aminoquinolines [cf. (V), (VII)] by inter-or intramolecular reductive coupling, resp., of a nitrile group with a nitro group induced by a low valent titanium reagent derived from TiCl 4 and Sm is reported. Scope and limitations of this method are discussed.-(

Tetrahedron, 1994

Enantioselective syntheses Enantioselective syntheses O 0031 Convenient Procedures for the Asymme... more Enantioselective syntheses Enantioselective syntheses O 0031 Convenient Procedures for the Asymmetric Reduction of 1,4-Diphenylbutane-1,4-dione and Synthesis of 2,5-Diphenylpyrrolidine Derivatives.-Different reduction agents in combination with proline reagents under various conditions are investigated. Diol (II) is transformed to the desired chiral auxiliaries (IV).

Tetrahedron-asymmetry, Feb 1, 1995

The racemic mixture of 2,2′-dihydroxy-1,1′-binaphthyl has been resolved to obtain the R(+) and S(... more The racemic mixture of 2,2′-dihydroxy-1,1′-binaphthyl has been resolved to obtain the R(+) and S(−) enantiomers in essentially pure forms by refluxing with (S)-proline (1eq.) in benzene in three successive operations. ... 5. M. Kawashima and A. Hirayama. Chem. Lett. ...

Journal of the Chemical Society, 1995

The borane complexes of (S)-(–)-N,N-dibenzyl-1-phenylethylamine 1. (S,S)-(–)-N,N-bis(1-phenylethy... more The borane complexes of (S)-(–)-N,N-dibenzyl-1-phenylethylamine 1. (S,S)-(–)-N,N-bis(1-phenylethyl)-1-phenylethylamine 2, (–)-2-phenyl-1-(1-phenylethyl)pyrrolidine 3, (–)-7-(1-phenylthyl)-4,5-dihydro-3H-dinaphth[2,3-c;2′,3′-e]azepine 4 and 1-(1-phenylethyl-3,4-diphenyl-pyrrolidine 5 have been prepared and used to reduce prochiral aromatic ketones to alcohols in 10–57% e.e. in the presence of BF3·OEt2. The complex 4·BF3 catalyses asymmetric reduction of acetophenone by N,N′-diethylaniIine–BH3 to give 1-phenylethyl alcohol in 51% e.e. A transition state consisting of a chiral amine·BF3·BH3 complex and the ketone is proposed to explain the transformation.

Organometallics, Mar 1, 1999

ABSTRACT

Journal of Organic Chemistry, Sep 1, 1991

Reduction of carboxylic acids to alcohols is an important transformation in synthetic organic che... more Reduction of carboxylic acids to alcohols is an important transformation in synthetic organic chemistry. Several methods are available for this purpose that utilize LiAlH, and boron Unfortunately, NaBH, does not reduce carboxylic acids under ambient condition^.^ We report here that carboxylic acids can be reduced directly to alcohols with some interesting selectivities by succesaive addition of NaBH, and I2 to RCOOH and RCOOH to NaBH, in T H F followed by 12.

ChemInform, May 23, 2010

Hydroboration. Part 97. Synthesis of New Exceptional Chloroborane-Lewis Base Adducts for Hydrobor... more Hydroboration. Part 97. Synthesis of New Exceptional Chloroborane-Lewis Base Adducts for Hydroboration. Dioxane-Monochloroborane as a Superior Reagent for the Selective Hydroboration of Terminal Alkenes.-Among several oxygen-containing Lewis bases, tested as mono-and dichloroborane carriers, only dioxane forms stable and reactive adducts. The dioxane-monochloroborane adduct hydroborates several representative olefins cleanly and rapidly. The corresponding alcohols are obtained in quantitative yields after oxidation. The hydroboration of several terminal olefins with this reagent proceeds with high regioselectivity to afford after oxidation primary alcohols such as (II) and (VI) almost exclusively. The dioxane-dichloroborane adduct shows remarkable selectivity toward 2substituted terminal olefins in the presence of terminal and other internal olefins as is demonstrated for limonene (III). In addition, the results of hydroborations using dichloroborane adducts of monoglyme and bis(β-chloroethyl) ether are also presented. These reagents also show high reactivity toward simple unhindered olefins. However, in the case of hindered olefins, the dichloroborane reagents require either refluxing conditions or BCl 3 as additive for efficient hydroborations.-(KANTH,

Tetrahedron, 1992

Reaction of amides with NaBli4-12 system in THF gives the corresponding amines in 70-76% yields. ... more Reaction of amides with NaBli4-12 system in THF gives the corresponding amines in 70-76% yields. Reduction of nitriles yields the corresponding amines in 70-75% yields.

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

ChemInform, Jun 27, 2011

Reinvestigation of Aminomethyltrifluoroborates and Their Application in Suzuki-Miyaura Cross-Coup... more Reinvestigation of Aminomethyltrifluoroborates and Their Application in Suzuki-Miyaura Cross-Coupling Reactions.-Treatment of borate (I) with amines does not yield the corresponding potassium borates but ammoniomethyltrifluoroborates of type (III). The latter smoothly undergo Suzuki-Miyaura cross-coupling with aromatic chlorides as well as bromides to afford aminomethylated arenes in good to high yields. Their transformation into the corresponding potassium borates, however,

ChemInform, Jun 14, 2010

Complexation of tertbutyldialkylamines (I) with BH 3 yields stable, highly reactive liquid adduct... more Complexation of tertbutyldialkylamines (I) with BH 3 yields stable, highly reactive liquid adducts, especially from (Ic), (Id), and (Ig), as borane carriers for hydroboration reactions, which can serve as eco-friendly substitutes for the currently popular hydroborating-reducing agents Me 2 S•BH 3 and THF•BH 3 .-(BROWN, HER

Journal of the Indian Institute of Science, Jan 2, 2013

Reactlorl olh(1.5 mole eq) w x '~ BHI.N(CB+PII (I cq 1 ui benmle at room lcmpmarure gwri R l i N(... more Reactlorl olh(1.5 mole eq) w x '~ BHI.N(CB+PII (I cq 1 ui benmle at room lcmpmarure gwri R l i N(C:H,):Ph reagent The BIi reagent prepaicd In th~a way oil rcact~ou wllh CIICOOH glve5 HI ~1 1~1 1 la !useful for hydroiodinatmn o f alkenes and alkymcs io &tam alhyl 2nd dhcnyl mdidcs In 74 to 84% jields. The BIi reagent 1s also useful for cicavigc o t N~caihnn~ntes to secondary amloz\. Appl~oarion of this rzngent ibr cleavage of ethers, esrers and suiphonnies is also d r c l h e d Key wards: lodoboiiine, alkyl and alhehyl lod~dr synthesis. clra\age of caibarnatc\, ethen. eltsrs and aulphooaies

Synthetic Communications, Feb 1, 1994

N-Benzyl tertiary amines on reaction with ethyl chloroformate give the corresponding debenzylated... more N-Benzyl tertiary amines on reaction with ethyl chloroformate give the corresponding debenzylated N-carbamates which on treatment with I3B:N(C2H5)2Ph complex yield the secondary amines.

Tetrahedron Letters, Jul 1, 1996

Abstract Reaction of low valent titanium reagent, prepared in situ in THF by the reduction of TiC... more Abstract Reaction of low valent titanium reagent, prepared in situ in THF by the reduction of TiCl 4 by Mg powder, with certain imines leads to the formation of imidazolidine derivatives in moderate to good yields.

ChemInform, Aug 4, 2010

Low-Valent Titanium Induced Reductive Coupling of Nitriles with Nitro Compounds.-A new method to ... more Low-Valent Titanium Induced Reductive Coupling of Nitriles with Nitro Compounds.-A new method to obtain amidines (III) and 2-aminoquinolines [cf. (V), (VII)] by inter-or intramolecular reductive coupling, resp., of a nitrile group with a nitro group induced by a low valent titanium reagent derived from TiCl 4 and Sm is reported. Scope and limitations of this method are discussed.-(

Tetrahedron, 1994

Enantioselective syntheses Enantioselective syntheses O 0031 Convenient Procedures for the Asymme... more Enantioselective syntheses Enantioselective syntheses O 0031 Convenient Procedures for the Asymmetric Reduction of 1,4-Diphenylbutane-1,4-dione and Synthesis of 2,5-Diphenylpyrrolidine Derivatives.-Different reduction agents in combination with proline reagents under various conditions are investigated. Diol (II) is transformed to the desired chiral auxiliaries (IV).

Tetrahedron-asymmetry, Feb 1, 1995

The racemic mixture of 2,2′-dihydroxy-1,1′-binaphthyl has been resolved to obtain the R(+) and S(... more The racemic mixture of 2,2′-dihydroxy-1,1′-binaphthyl has been resolved to obtain the R(+) and S(−) enantiomers in essentially pure forms by refluxing with (S)-proline (1eq.) in benzene in three successive operations. ... 5. M. Kawashima and A. Hirayama. Chem. Lett. ...

Journal of the Chemical Society, 1995

The borane complexes of (S)-(–)-N,N-dibenzyl-1-phenylethylamine 1. (S,S)-(–)-N,N-bis(1-phenylethy... more The borane complexes of (S)-(–)-N,N-dibenzyl-1-phenylethylamine 1. (S,S)-(–)-N,N-bis(1-phenylethyl)-1-phenylethylamine 2, (–)-2-phenyl-1-(1-phenylethyl)pyrrolidine 3, (–)-7-(1-phenylthyl)-4,5-dihydro-3H-dinaphth[2,3-c;2′,3′-e]azepine 4 and 1-(1-phenylethyl-3,4-diphenyl-pyrrolidine 5 have been prepared and used to reduce prochiral aromatic ketones to alcohols in 10–57% e.e. in the presence of BF3·OEt2. The complex 4·BF3 catalyses asymmetric reduction of acetophenone by N,N′-diethylaniIine–BH3 to give 1-phenylethyl alcohol in 51% e.e. A transition state consisting of a chiral amine·BF3·BH3 complex and the ketone is proposed to explain the transformation.

Organometallics, Mar 1, 1999

ABSTRACT

Journal of Organic Chemistry, Sep 1, 1991

Reduction of carboxylic acids to alcohols is an important transformation in synthetic organic che... more Reduction of carboxylic acids to alcohols is an important transformation in synthetic organic chemistry. Several methods are available for this purpose that utilize LiAlH, and boron Unfortunately, NaBH, does not reduce carboxylic acids under ambient condition^.^ We report here that carboxylic acids can be reduced directly to alcohols with some interesting selectivities by succesaive addition of NaBH, and I2 to RCOOH and RCOOH to NaBH, in T H F followed by 12.

ChemInform, May 23, 2010

Hydroboration. Part 97. Synthesis of New Exceptional Chloroborane-Lewis Base Adducts for Hydrobor... more Hydroboration. Part 97. Synthesis of New Exceptional Chloroborane-Lewis Base Adducts for Hydroboration. Dioxane-Monochloroborane as a Superior Reagent for the Selective Hydroboration of Terminal Alkenes.-Among several oxygen-containing Lewis bases, tested as mono-and dichloroborane carriers, only dioxane forms stable and reactive adducts. The dioxane-monochloroborane adduct hydroborates several representative olefins cleanly and rapidly. The corresponding alcohols are obtained in quantitative yields after oxidation. The hydroboration of several terminal olefins with this reagent proceeds with high regioselectivity to afford after oxidation primary alcohols such as (II) and (VI) almost exclusively. The dioxane-dichloroborane adduct shows remarkable selectivity toward 2substituted terminal olefins in the presence of terminal and other internal olefins as is demonstrated for limonene (III). In addition, the results of hydroborations using dichloroborane adducts of monoglyme and bis(β-chloroethyl) ether are also presented. These reagents also show high reactivity toward simple unhindered olefins. However, in the case of hindered olefins, the dichloroborane reagents require either refluxing conditions or BCl 3 as additive for efficient hydroborations.-(KANTH,

Tetrahedron, 1992

Reaction of amides with NaBli4-12 system in THF gives the corresponding amines in 70-76% yields. ... more Reaction of amides with NaBli4-12 system in THF gives the corresponding amines in 70-76% yields. Reduction of nitriles yields the corresponding amines in 70-75% yields.

Self-suspending proppant transport technology comprises a 1-micron to 3-micron thick, residue-fre... more Self-suspending proppant transport technology comprises a 1-micron to 3-micron thick, residue-free, water-swellable, shear-stable polymer coating applied to a proppant substrate. The polymer swells upon contact with water, temporarily reducing the proppant's effective specific gravity. This lower effective specific gravity enables uniform vertical proppant distribution throughout the fracture. The polymer coating, which is broken and unzipped with conventional oxidative breakers, flows back freely with the frac fluid. This paper examines how the use of this water-swellable polymer coating around a proppant minimizes the negative affect on proppant pack conductivity and formation permeability that occurs with common viscosifying agents and friction reducers. This paper also documents how the technology increases stimulated reservoir area and increases production by reducing net formation damage near-wellbore and deep in the formation. These dynamics have been evaluated and confirmed through laboratory data and field-trial wells that were completed with various combinations of frac fluid systems. Results show a complete removal of the water-soluble polymer coating, preventing formation damage. In this paper, the authors include detailed laboratory test methods and results, including static and dynamic viscometrics on supernatant and proppant-laden fluids, settled bed height comparisons, and loss on ignition. Regain conductivity and retained permeability tests are compared with conventional fluid systems. Further, these results are confirmed by analytical test methods. These tests confirm the self-suspending proppant polymer coating leaves little to no residue in the formation. Self-suspending proppant technology field performance data confirm a better production scenario in the absence of formation-damaging fracturing fluid. Further, operators achieved the best results when only using this new technology without other proppant or other fluid systems. In 3 formations after 18 months, 6 months, and 5 months, hydrocarbon production in the wells with self-suspending proppant technology increased 45%, 7%, and 43% compared with their respective offset test wells. The test results and field data described in this paper prove the value of reducing formation damage to improve well performance.