Cycloadditions of Alkenylboronic Derivatives

Abstract

The literature on cycloaddition reactions of boron-containing alkenes is surveyed with 132 references. The data are categorized according to the reaction type ([2+1], [2+2], [3+2], [4+2], and [4+3] cycloadditions). The cyclopropanation and the Diels–Alder reactions of alkenylboronic derivatives have been studied more or less comprehensively, and for some substrates, they can be considered as convenient methods for the rapid regio- and stereoselective construction of even complex cyclic systems. Other types of the cycloadditions, as well as mechanistic aspects of the processes, have been addressed less thoroughly in the previous works.1 Introduction2 [2+1] Cycloaddition2.1 Cyclopropanation2.1.1 With Methylene Synthetic Equivalents2.1.2 With Substituted Carbenoids2.2 Epoxidation2.3 Aziridination3 [2+2] Cycloaddition4 [3+2] Cycloaddition4.1 With Nitrile Oxides4.2 With Diazoalkanes4.3 With Nitrones4.4 With Azomethine Ylides5 [4+2] Cycloaddition6 [4+3] Cycloaddition7 Conclusions and Outlook

Emerging Building Blocks for Medicinal Chemistry: Recent Synthetic Advances

“…The key literature data on these strategies were collected in recent reviews. [91,92] Also, (iii) modification of alkenylboron compounds 8 (e. g. via the cycloaddition reactions reviewed by our group recently [93] ) can be mentioned.…”

Saturated Boronic Acids, Boronates, and Trifluoroborates: An Update on Their Synthetic and Medicinal Chemistry

“…The key literature data on these strategies were collected in recent reviews. [58,166,167] Apart from modified or improved versions of the aforementioned methods, a number of novel approaches to the synthesis of saturated (hetero)aliphatic organoboron compounds appeared recently. These include iv) boronation of alkyl halides and sulfonates; v) decarboxylative boronation; vi) deoxygenative boronation; vii) deaminative boronation; viii) boronation through CÀ H activation; ix) novel approaches to alkene hydroboration (both Markovnikov and anti-Markovnikov); x) alkene carbo-and heteraboration; xi) 1,2-metallate rearrangements (i. e., Matteson homologation); xii) "strain-release" organoboron It should be noted that some aspects of the aforementioned approaches (i. e., radical CÀ B bond-forming reactions, [7] as well as transition metal-free methods [168] ) were reviewed recently.…”

Synthesis of Tri‐ and Tetrasubstituted Alkenyl Boronates from Alkynes

“…Transformations of the boryl motif of organoboronates into a range of functional groups are also well known, including protodeboronation, oxidation, amination and the Chan‐Lam coupling, many of which have been developed stereospecifically from enantioenriched secondary and tertiary boronic esters [4] . In addition to those processes, the family of alkenyl boronates are key precursors in cycloaddition reactions (cyclopropanation, epoxidation, aziridination, [2+2], [3+2] and [4+2]) for the preparation of cycloalkylboronates and boryl‐substituted saturated heterocycles [5] . Other useful transition metal‐catalyzed transformations from alkenyl boronates include the Wacker oxidation, which led to α‐borylated ketones, [6] the C(sp 2 )−H alkenylation of aromatic rings and the C(sp 3 )−H vinylation of cyclopropanes [7]…”