MIDA (1-cyclohexyl-2-oxoethyl)boronate;Cyclohexyl-alpha-MIDA-boryl aldehyde;2-cyclohexyl-2-(5-methyl-3,7-dioxo-2,8-dioxa-5-azonia-1-boranuidabicyclo[3.3.0]octan-1-yl)acetaldehyde
已经证明了 α-硼烯胺和烯酰胺在氮杂环合成中的使用。硼烯胺可以很容易地获得相应的 α-卤代醛,这些醛经过区域选择性环化形成硼化噻唑。缩合/酰胺化序列将 α-硼醛转化为稳定的 α-硼烯酰胺,而不会伴随 C → N 迁移。我们还表明,钯催化的 α-硼烯酰胺环化导致合成通用的异吲哚酮。这些分子随后可用于访问多环支架。
A new class of stable molecules, alpha-boryl aldehydes, has been prepared from oxiranyl N-methyliminodiacetyl boronates by a 1,2-boryl migration with concomitant epoxide scission. A range of boryl imines, alkenes, alcohols, acids, enol ethers, enamides, and other functionalized boronic acid derivatives that are difficult or impossible to prepare using established protocols can be accessed from alpha-boryl aldehydes. The chemoselective transformations of these building blocks, including the facile synthesis of functionalized unnatural amino acids from silyloxy and amido vinyl boronates, attest to the potential of alpha-boryl aldehydes in chemical synthesis.
Boroalkyl Group Migration Provides a Versatile Entry into α-Aminoboronic Acid Derivatives
作者:Zhi He、Adam Zajdlik、Jeffrey D. St. Denis、Naila Assem、Andrei K. Yudin
DOI:10.1021/ja304173d
日期:2012.6.20
exemplifying migration of boron-substituted carbon is described. We show that α-boroalkyl groups of transient boroalkyl acyl azide intermediates readily migrate from carbon to nitrogen. This process allows access to a new class of stable molecules, α-boryl isocyanates, from α-borylcarboxylic acid precursors. The methodology facilitates synthesis of a wide range of α-aminoboronic acid derivatives, including
Synthesis of Aminoboronic Acid Derivatives from Amines and Amphoteric Boryl Carbonyl Compounds
作者:Diego B. Diaz、Conor C. G. Scully、Sean K. Liew、Shinya Adachi、Piera Trinchera、Jeffrey D. St. Denis、Andrei K. Yudin
DOI:10.1002/anie.201605754
日期:2016.10.4
Herein, we demonstrate the use of α‐boryl aldehydes and acyl boronates in the synthesis of aminoboronic acid derivatives. This work highlights the untapped potential of boron‐substituted iminium ions and offers insights into the behavior of N‐methyliminodiacetyl (MIDA) boronates during condensation and tautomerization processes. The preparative value of this contribution lies in the demonstration that