SYNTHESIS AND PROPERTIES OF PINANEDIOL ALPHA-AMIDO BORONIC ESTERS
SYNTHESIS AND PROPERTIES OF PINANEDIOL ALPHA-AMIDO BORONIC ESTERS
复制标题
DOI：
10.1021/om00086a024
复制
发表时间：
1984-01-01
期刊：
影响因子：
2.8
通讯作者：
SADHU, KM
中科院分区：
文献类型：
--
作者：
MATTESON, DS;JESTHI, PK;SADHU, KM
已经探索了使用（+）-蒎烷二醇作为手性导向基团用于合成几种α（R）-α-酰胺基硼酸酯和硼酸，它们是N-酰基-L-氨基酸的硼酸类似物。RB 02 Pin（Pin=顺式-蒎烷-2，3-二基）与（S）-RCHClB 02 Pin同源，其通过先前报道的方法转化为（R）-RCH-（NHAc）B 02 Pin，并且对于R=异丙基，转化为（R）-RCH（NHCOAc）B（OH）2。当R=异丁基、甲基或（苄氧基）甲基时，同系化步骤需要氯化锌催化。以（-）-蒎烷二醇为原料合成了两种（S）-乙酰氨基硼酸酯（R=异丙基、异丁基）。不稳定的氨基硼酸酯中间体与苄氧羰基氯的酰化在PhCH 2CH（NHC 00 CH 2 Ph）B 〇 2 Pin的合成中完成，但是将蒎烷二醇硼酸酯裂解为酸的不稳定的硼也裂解苄氧基。烯丙基卤化物或烯丙基苄基醚与（1，2-苯二氧基）硼烷的硼氢化反应产生了β-取代的硼酸酯。将这些转化为（H-）-蒎烷二醇酯，并通过上述一般途径转化为乙酰氨基取代的硼酸酯。已经制备了（蒎烷二基二氧基）硼烷，并且发现其是一种缓慢的硼氢化剂。
The use of (+)-pinanediol as the chiral directing group for the synthesis of several a (R)-a-amido boronic esters and acids, which are boronic acid analogues of iV-acyl-L-amino acids, has been explored. RB02Pin (Pin= cts-pinane-2, 3-diyl) was homologated to (S)-RCHClB02Pin, which was converted to (R)-RCH-(NHAc) B02Pin and, for R= isopropyl, to CR)-RCH (NHCOAc) B (OH) 2 by previously reported methods. Where R= isobutyl, methyl, or (benzyloxy) methyl, zinc chloride catalysis was required for the homologation step. Two (S)-acetamido boronic esters (R= isopropyl, isobutyl) were made from (-)-pinanediol. Acylation of the unstable-amino boronic ester intermediate with carbobenzyloxy chloride was accomplished in the synthesis of PhCH2CH (NHC00CH2Ph) B02Pin, but attemptedboron trichloride cleavage of the pinanediol boronic ester to the acid also cleaved the benzyloxy group. Hydroboration of allyl halides or allyl benzyl ether with (1, 2-phenyldioxy) borane has yielded^-substituted boronic esters. These were converted to (H-)-pinanediol esters and converted by the general route outlined above to-acetamido¿-substituted boronic esters.(Pinanediyldioxy) borane has been prepared and found to be a sluggish hydroborating agent.