Full chirality transfer in the synthesis of hindered tertiary boronic esters under in situ lithiation–borylation conditions
作者:D. J. Blair、S. Zhong、M. J. Hesse、N. Zabaleta、E. L. Myers、V. K. Aggarwal
DOI:10.1039/c6cc00536e
日期:——
Using non-cryogenic lithiation-borylation, sterically hindered tertiary neopentyl glycol boronicesters can be prepared from secondary benzylic carbamates with full chirality transfer.
使用非低温锂化-硼酸化,可以从具有完全手性转移的仲苄基氨基甲酸酯制备位阻叔新戊二醇硼酸酯。
Magnesium promoted autocatalytic dehydrogenation of amine borane complexes: A reliable, non-cryogenic, scalable access to boronic acids
作者:Ludovic D. Marciasini、Jimmy Richard、Bastien Cacciuttolo、Guillaume Sartori、Melodie Birepinte、Laurent Chabaud、Sandra Pinet、Mathieu Pucheault
DOI:10.1016/j.tet.2018.11.036
日期:2019.1
access boronic acids. The intrinsic instability of magnesium aminoborohydride was tweaked into a tandem dehydrogenation borylation sequence. Proceeding via an autocatalytic cycle, amineborane dehydrogenation was induced by a variety of Grignard reagents. Overall, addition of the organomagnesium species onto specially designed dialkylamine-borane complexes led to a variety of boronic acids in high yields
Alkynyl Moiety for Triggering 1,2‐Metallate Shifts: Enantiospecific sp
<sup>2</sup>
–sp
<sup>3</sup>
Coupling of Boronic Esters with
<i>p</i>
‐Arylacetylenes
作者:Venkataraman Ganesh、Marcin Odachowski、Varinder K. Aggarwal
DOI:10.1002/anie.201703894
日期:2017.8.7
The enantiospecific coupling of secondary and tertiary boronic esters to aromatics has been investigated. Using p-lithiated phenylacetylenes and a range of boronic esters coupling has been achieved by the addition of N-bromosuccinimide (NBS). The alkyne functionality of the intermediate boronate complex reacts with NBS triggering the 1,2-migration of the group on boron to carbon giving a dearomatized
Factors Affecting Migration of Tertiary Alkyl Groups in Reactions of Alkylboronic Esters with Bromomethyllithium
作者:Mark C. Elliott、Keith Smith、D. Heulyn Jones、Ajaz Hussain、Basil A. Saleh
DOI:10.1021/jo4000459
日期:2013.4.5
be of great potential for the formation of quaternary carbon centers but often give poor yields/conversions. Calculations and experimental evidence show that tert-alkyl groups migrate less effectively than other types of alkylgroup in such reactions and that O-migration competes. Furthermore, slow/incomplete capture of the bromomethyl reagent by the boronic ester is a problem in more hindered systems
Practical and efficient applications of novel dioxaborolanes and dioxaborinanes in the synthesis of corresponding boronates and their use in the palladium-catalyzed cross coupling reactions
作者:Malgorzata Myslinska、Glenn L. Heise、Dana J. Walsh
DOI:10.1016/j.tetlet.2012.03.048
日期:2012.6
from the reaction of dioxaborolanes and dioxaborinanes with either organolithium or organomagnesium reagents are investigated along with their subsequent use in the palladium cross coupling reaction. The intrinsic stability of these cyclic esters contributes to their facile reaction with both lithium and magnesium nucleophiles at mild and safe conditions. We have found that many of the reactions proceed