Publications

2022
Nagaraju Anugula, Saiaede, Tamer , Eghbarieh, Nadim , and Masrawa*, Ahmad . 2022. Photoredox-Mediated Deoxygenative Radical Additions Of Aromatic Acids To Vinyl Boronic Esters And Gem-Diborylalkenes. Chemistry—A European Journal, Pp. e202202646. . Publisher's Version
Nicole Hanania, Nassir, Molhm , Eghbarieh, Nadim , and Masarwa*, Ahmad . 2022. A Stereodivergent Approach To The Synthesis Of Gem-Diborylcyclopropanes. Chemistry—A European Journal, Pp. e202202748. . Publisher's Version
2021
Nadim Eghbarieh, Hanania, Nicole , Zamir, Alon , Nassir, Molhm , Stein, Tamar , and Masarwa*, Ahmad . 2021. Stereoselective Diels-Alder Reactions Of Gem-Diborylalkenes: Toward The Synthesis Of Gem-Diboron-Based Polymers. Journal Of The American Chemical Society, 143, 143, Pp. 6211-6220. . Publisher's Version Abstract
Although gem-diborylalkenes are known to be among the most valuable reagents in modern organic synthesis, providing a rapid access to a wide array of transformations, including the construction of C-C and C-heteroatom bonds, their use as dienophile-reactive groups has been rare. Herein we report the Diels-Alder (DA) reaction of (unsymmetrical) gem-diborylalkenes. These reactions provide a general and efficient method for the stereoselective conversion of gem-diborylalkenes to rapidly access 1,1-bisborylcyclohexenes. Using the same DA reaction manifold with borylated-dienes and gem-diborylalkenes, we also developed a concise, highly regioselective synthesis of 1,1,2-tris- and 1,1,3,4-tetrakis(boronates)cyclohexenes, a family of compounds that currently lack efficient synthetic access. Furthermore, DFT calculations provided insight into the underlying factors that control the chemo-, regio, and stereoselectivity of these DA reactions. This method also provides stereodivergent syntheses of gem-diboryl-norbornenes. The utility of the gem-diboryl-norbornene building blocks was demonstrated by ring-opening metathesis polymerization (ROMP), providing a highly modular approach to the first synthesis of the gem-diboron-based polymers. Additionally, these polymers have been successfully submitted to post-polymerization modification reactions. Given its simplicity and versatility, we believe that this novel DA and ROMP approach holds great promise for organoboron synthesis as well as organoboron-based polymers and that it will result in more novel transformations in both academic and industrial research.
2020
Nivesh Kumar, Eghbarieh, Nadim , Stein, Tamar , Shames, Alexander I. , and Masarwa*, Ahmad . 2020. Photoredox-Mediated Reaction Of Gem-Diborylalkenes: Reactivitytoward Diverse 1,1-Bisborylalkanes. Chemistry—A European Journal, 26, Pp. 5360. . Publisher's Version Abstract
The use of gem-diborylalkenes as light-reactive groups is explored for the first time. These reactions provide an efficient and general method for the photochemical conversion of gem-diborylalkenes to rapidly access 1,1-bisborylalkanes. This method exploits a novel photoredox decarboxylative radical addition to gem-diborylalkenes to afford α-gemdiboryl carbon-centered radicals, which benefit from additional stability by virtue of an interaction with the empty p-orbitals on borons. The reaction offers a highly modular and regioselective approach to γ-amino gem-diborylalkanes. Furthermore, EPR spectroscopy and DFT calculations have provided insight into the radical mechanism underlying the photochemistry reaction.
Rajender Nallagonda, Kumar, Nivesh , Reddy, Reddy Rajasekhar , Shioukhi, Israa , Sagih, Hila , and Masarwa*, Ahmad . 2020. Synthesis And Reactivity Of 1,1 And 1,2-Bisboronate Species. (Patai’s Chemistry Of Functional Groups) John Wiley & Sons, Chichester, England. . Publisher's Version Abstract
In the past four decades, the chemistry of 1,1- and 1,2-bisboronate compounds has been extensively explored. Many interesting structural features and reaction patterns have emerged, and more importantly, these compounds now feature prominently in both metal-catalyzed and metal-free transformations for the formation of CC bonds and C–heteroatom and other processes. This chapter aims to highlight the recent development in this rising research field, focusing on the synthesis of 1,1- and 1,2-bisboronate compounds and their reactivity and selectivity that originate from the use of these bisboronates.
K. Naresh Babu, Massarwe, Fedaa , Reddy, Reddy Rajasekhar , Eghbarieh, Nadim , Jakob, Manuella , and Masarwa*, Ahmad . 2020. Unsymmetrical 1,1-Bisboryl Species: Valuable Building Blocks In Synthesis. Molecules, 25, Pp. 959. . Publisher's Version Abstract
Unsymmetrical 1,1-bis(boryl)alkanes and alkenes are organo-bismetallic equivalents, which are synthetically important because they allow for sequential selective transformations of C–B bonds. We reviewed the synthesis and chemical reactivity of 1,1-bis(boryl)alkanes and alkenes to provide information for the synthetic community. In the first part of this review, we disclose the synthesis and chemical reactivity of unsymmetrical 1,1-bisborylalkanes. In the second part, we describe the synthesis and chemical reactivity of unsymmetrical 1,1-bis(boryl)alkenes.  
Nivesh Kumar, Reddy, Reddy Rajasekhar , Eghbarieh, Nadim , and Masarwa*, Ahmad . 2020. Α-Borylalkyl Radicals: Their Distinctive Reactivity In Modern Organic Synthesis. Chemical Communications, 56, Pp. 13-25. . Publisher's Version Abstract
Organoborons are extremely important for synthetic organic chemistry; they can serve as advanced intermediates for a variety of transformations. Such a well-known transformation involves the loss of the boron moiety, creating alkyl radicals. Although these originally developed protocols for alkyl radical generation remain in active use today, in recent years their α-boryl carbon-centred radicles have been joined by a new array of radical generation strategies that offer a unique reactivity to forge a wider diversity of organoborones that often operate under mild and benign conditions. Herein, we will highlight the stability and reactivity of α-borylalkyl radicals and their remarkably recent advances in order to further utilise them for C–C and C–heteroatom bond formation. Their use for this purpose has been reported over the last decade in an attempt to guide the synthetic community. Various transition-metal and metal-free methods for their generation are presented, and more advanced photoredox approaches are discussed, mainly for the period of time 2009-2019.
Nivesh Kumar, Eghbarieh, Nadim , Stein, Tamar , Shames, Alexander I. , and Masarwa*, Ahmad . 2020. Photoredox-Mediated Reaction Of Gem-Diborylalkenes: Reactivitytoward Diverse 1,1-Bisborylalkanes. Chemistry—A European Journal, 26, Pp. 5360. . Publisher's Version Abstract

The use of gem-diborylalkenes as light-reactive groups is explored for the first time. These reactions provide an efficient and general method for the photochemical conversion of gem-diborylalkenes to rapidly access 1,1-bisborylalkanes.

This method exploits a novel photoredox decarboxylative radical addition to gem-diborylalkenes to afford α-gemdiboryl carbon-centered radicals, which benefit from additional stability by virtue of an interaction with the empty p-orbitals on borons. The reaction offers a highly modular and regioselective approach to γ-amino gem-diborylalkanes. Furthermore, EPR spectroscopy and DFT calculations have provided insight into the radical mechanism underlying the photochemistry reaction.

DDDD

Rajender Nallagonda, Kumar, Nivesh , Reddy, Reddy Rajasekhar , Shioukhi, Israa , Sagih, Hila , and Masarwa*, Ahmad . 2020. Synthesis And Reactivity Of 1,1 And 1,2-Bisboronate Species. (Patai's Chemistry Of Functional Groups) John Wiley & Sons, Chichester, England . . Publisher's Version Abstract

In the past four decades, the chemistry of 1,1‐ and 1,2‐bisboronate compounds has been extensively explored. Many interesting structural features and reaction patterns have emerged, and more importantly, these compounds now feature prominently in both metal‐catalyzed and metal‐free transformations for the formation of CC bonds and C–heteroatom and other processes. This chapter aims to highlight the recent development in this rising research field, focusing on the synthesis of 1,1‐ and 1,2‐bisboronate compounds and their reactivity and selectivity that originate from the use of these bisboronates.

K. Naresh Babu, Massarwe, Fedaa , Reddy, Reddy Rajasekhar , Eghbarieh, Nadim , Jakob, Manuella , and Masarwa*, Ahmad . 2020. Unsymmetrical 1,1-Bisboryl Species: Valuable Building Blocks In Synthesis. Molecules , 25, Pp. 959. . Publisher's Version Abstract

Unsymmetrical 1,1-bis(boryl)alkanes and alkenes are organo-bismetallic equivalents, which are synthetically important because they allow for sequential selective transformations of C–B bonds. We reviewed the synthesis and chemical reactivity of 1,1-bis(boryl)alkanes and alkenes to provide information for the synthetic community. In the first part of this review, we disclose the synthesis and chemical reactivity of unsymmetrical 1,1-bisborylalkanes. In the second part, we describe the synthesis and chemical reactivity of unsymmetrical 1,1-bis(boryl)alkenes.

 

MOLECULES1

Nivesh Kumar, Reddy, Reddy Rajasekhar , Eghbarieh, Nadim , and Masarwa*, Ahmad . 2020. Α-Borylalkyl Radicals: Their Distinctive Reactivity In Modern Organic Synthesis. Chemical Communications, 56, Pp. 13-25. . Publisher's Version Abstract

Organoborons are extremely important for synthetic organic chemistry; they can serve as advanced intermediates for a variety of transformations. Such a well-known transformation involves the loss of the boron moiety, creating alkyl radicals. Although these originally developed protocols for alkyl radical generation remain in active use today, in recent years their α-boryl carbon-centred radicles have been joined by a new array of radical generation strategies that offer a unique reactivity to forge a wider diversity of organoborones that often operate under mild and benign conditions. Herein, we will highlight the stability and reactivity of α-borylalkyl radicals and their remarkably recent advances in order to further utilise them for C–C and C–heteroatom bond formation. Their use for this purpose has been reported over the last decade in an attempt to guide the synthetic community. Various transition-metal and metal-free methods for their generation are presented, and more advanced photoredox approaches are discussed, mainly for the period of time 2009-2019.

chem 2

2019
Nivesh Kumar, Reddy, Reddy Rajasekhar , and Masarwa*, Ahmad . 2019. Stereoselective Desymmetrization Of Gem-Diborylalkanes By &Ldquo;Trifluorination&Rdquo;. Chemistry – A European Journal, 25, Pp. 8008-8012. . Publisher's Version Abstract
An efficient and general method for the chemoselective synthesis of unsymmetrical gem-diborylalkanes is reported. This method is based on a novel late-stage desymmetrization via nucleophilic “trifluorination”, providing chiral gem-diborylalkanes bearing a trifluoroborate group. The reaction offers a highly modular and diastereoselective approach to synthesize gem-diborylcyclopropanes. The utility of the gem-diborylalkane building blocks was demonstrated by selective post-functionalization of the trifluoroborate group. These functionalizations include inter- and intra- Pd-catalyzed Suzuki-Miyaura coupling reactions. 
Nivesh Kumar, Reddy, Reddy Rajasekhar , and Masarwa*, Ahmad . 2019. Stereoselective Desymmetrization Of Gem-Diborylalkanes By &Ldquo;Trifluorination&Rdquo;. Chemistry – A European Journal, 25, Pp. 8008-8012. . Publisher's Version Abstract

An efficient and general method for the chemoselective synthesis of unsymmetrical gem-diborylalkanes is reported. This method is based on a novel late-stage desymmetrization via nucleophilic “trifluorination”, providing chiral gem-diborylalkanes bearing a trifluoroborate group. The reaction offers a highly modular and diastereoselective approach to synthesize gem-diborylcyclopropanes. The utility of the gem-diborylalkane building blocks was demonstrated by selective post-functionalization of the trifluoroborate group. These functionalizations include inter- and intra- Pd-catalyzed Suzuki−Miyaura coupling reactions.

a

2018
Rajender Nallagonda, Padala, Kishor , and Masarwa*, Ahmad . 2018. Gem-Diborylalkanes: Recent Advances In Their Preparation, Transformation And Application. Org. Biomol. Chem., 16, Pp. 1050 - 1064. . Publisher's Version Abstract
Recently, gem-diborylalkanes have attracted much attention as versatile building blocks and fundamental intermediates in organic synthesis, because they enable multiple C–C bond construction and further transformation at C–B bonds. Importantly, gem-diborylalkanes can be utilised as bisnucleophilic partners in a variety of chemo-selective C–C bond-forming reactions. This review describes recent developments in synthesising gem-diborylalkanes in complex molecules along with their chemical transformation. In the first part of the review the different synthetic approaches used to synthesise gem-diborylalkanes are described. In the second part, an overview of the chemoselective transformation of gem-diborylalkanes into various functionalized materials is discussed along with one-carbon homologation of diborylmethane via a selective uni- and bidirectional method.