作者:Chao Li、Jie Wang、Lisa M. Barton、Shan Yu、Maoqun Tian、David S. Peters、Manoj Kumar、Antony W. Yu、Kristen A. Johnson、Arnab K. Chatterjee、Ming Yan、Phil S. Baran
DOI:10.1126/science.aam7355
日期:2017.6.9
functionalized alkyl boronate esters from abundant carboxylic substituents. This broad-scope nickel-catalyzed reaction uses the same activating principle as amide bond formation to replace a carboxylic acid moiety with a boronate ester. Application to peptides allowed expedient preparations of α-amino boronic acids, often with high stereoselectivity, thereby facilitating synthesis of the alkyl boronic acid drugs
An electrochemically promoted decarboxylativeborylation reaction is reported. The reaction proceeds under mild conditions in an undivided cell without use of transition metal- or photo-catalysts. The key feature of the reaction is the compatibility of diboron reagents with the electrochemical conditions. This reaction exhibits broad substrate scope, good functional group tolerability, and easy scalability
The direct, stereospecific amination of alkylboronic and borinic esters can be conducted by treatment of the organoboron compound with methoxyamine and potassium tert-butoxide. In addition to being stereospecific, this process also enables the direct amination of tertiary boronic esters in an efficient fashion.
Nickel-Catalyzed Coupling Reactions of Alkyl Electrophiles, Including Unactivated Tertiary Halides, To Generate Carbon–Boron Bonds
作者:Alexander S. Dudnik、Gregory C. Fu
DOI:10.1021/ja304068t
日期:2012.6.27
examples of coupling reactions of unactivated tertiaryalkyl electrophiles, as well as our first success with nickel-catalyzed couplings that generate bonds other than C-C bonds. Specifically, we have determined that this catalyst accomplishes Miyaura-type borylations of unactivated tertiary, secondary, and primary alkylhalides with diboron reagents to furnish alkylboronates, a family of compounds with substantial
通过使用NiBr(2)·二甘醇二甲醚原位形成的催化剂和pybox配体(两者均可商购),我们实现了未活化叔烷基亲电试剂偶联反应的第一个实例,并取得了首次成功镍催化偶联产生除 CC 键以外的键。具体来说,我们已经确定,这种催化剂在温和条件下完成了未活化的叔、仲和伯烷基卤化物与二硼试剂的宫浦型硼酸化反应,以提供烷基硼酸酯,这是一个具有实质性(并扩大)效用的化合物家族;事实上,叔烷基溴的 umpolung 硼酸化可以在低至 -10 °C 的温度下实现。该方法表现出良好的官能团兼容性和区域特异性,这两者都可能是合成烷基硼酸酯的传统方法的问题。与看似相关的镍催化 CC 键形成过程相反,在这种镍催化的 CB 键形成反应中,叔卤化物比仲卤化物或伯卤化物更具反应性;鉴于两种转化都可能遵循氧化加成的内球电子转移途径,这种差异尤其值得注意。
Controllable Regiodivergent Alkynylation of 1,3‐Bis(Boronic) Esters Activated by Distinct Organometallic Reagents
作者:Ang Chen、Yang Qiao、De‐Wei Gao
DOI:10.1002/anie.202312605
日期:2023.11.27
An efficient method for controllable regiodivergent alkynylation of 1,3-bis(boronic) esters using distinct organometallicreagents has been developed. Mechanistic studies revealed that unique chelation patterns are essential in determining selectivity. This approach overcomes the drawbacks associated with coupling reactions through radical mechanisms, which commonly yield the classical products reacting