Protecting-group-free diastereoselective C-C coupling of 1,3-glycols and allyl acetate through site-selective primary alcohol dehydrogenation.
Protecting-group-free diastereoselective C-C coupling of 1,3-glycols and allyl acetate through site-selective primary alcohol dehydrogenation.
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DOI：
10.1002/anie.201209863
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发表时间：
2013-03-11
影响因子：
16.6
通讯作者：
Krische, Michael J.
中科院分区：
文献类型：
--
作者：
Dechert-Schmitt, Anne-Marie R.;Schmitt, Daniel C.;Krische, Michael J.
区分相似官能团的能力，从而以位点选择性或化学选择性的方式转化有机分子，[1]排除了对保护基团的要求，因此具有显着提高合成效率的潜力。[2]虽然是一个非常艰巨的挑战，系统的努力，催化方法的多官能分子的位点选择性转化已经开始出现。例如，米勒[3]和泰勒[4]的小组报告了用于二醇和高级多元醇的位点选择性操作的催化方法。位点选择性金属催化的交叉偶联已被编目。[5]此外，在位点选择性的最可怕的领域，C3 H4官能化的催化方法已经取得了令人印象深刻的进展，如巴顿，[6 b] Murai和Kakiuchi的开创性工作，[6a]以及Davies，[6c] Sanford，[6d] Yu，[6 e] Daugulis，[6 f] Baran，[6 g]和其他人最近的研究所示。尽管已经报道了用于位点选择性二醇氧化的方法，包括铱催化的方法，[7，8]涉及化学选择性多元醇氧化的合并的氧化还原-CCl 2C键构建事件是未知的。[9]结合正在进行的C13 C键形成氢化的研究，我们最近发现某些铱和钌络合物催化伯醇和p-不饱和反应物之间的氢交换以产生有机醛-醛对，所述有机醛-醛对联合收割机结合以形成羰基加成产物。[10]在这些转化中，伯醇反应物会被氧化，而仲醇产物则不会。这一事实，以及在水性有机介质中进行某些转移氢化偶联的能力，表明未保护的多元醇可能参与位点选择性甲醇CH-官能化。本文中，我们报道了衍生自（R）-或（S）-segphos（segphos= 5，5 '-双（二苯基膦基）-4，4'-双-1，3-苯并间二氧杂环戊烯）和4-氰基-3-硝基苯甲酸的环化的对烯丙基铱C，O-苯甲酸盐络合物催化未保护的二醇和高级多元醇的氧化还原触发的烯丙基化[11，12]，具有对伯醇脱氢的显著动力学偏好。以这种方式，在不存在保护基团、手性助剂、预金属化试剂和离散的醇至醛氧化的情况下实现多元醇的化学和立体选择性甲醇CH-烯丙基化（方案1）。
The ability to discriminate between like functional groups, so as to transform organic molecules in a site-selective or chemoselective manner,[1] precludes the requirement of protecting groups and, hence, carries the potential to dramatically enhance synthetic efficiency.[2] Though an exceptionally daunting challenge, systematic efforts toward catalytic methods for the site-selective transformation of polyfunctional molecules have begun to emerge. For example, the groups of Miller [3] and Taylor [4] report catalytic methods for the site-selective manipulation of diols and higher polyols. Site-selective metal-catalyzed cross-couplings have been catalogued.[5] Further, in what is perhaps the most formidable theatre for site selectivity, impressive advances in catalytic methods for CÀH functionalization have been achieved, as illustrated in the seminal work of Barton,[6b] Murai and Kakiuchi,[6a] and in more recent studies by the groups of Davies,[6c] Sanford,[6d] Yu,[6e] Daugulis,[6f] Baran,[6g] and others. Although methods for site-selective diol oxidation have been reported, including iridium catalyzed methods,[7, 8] merged redox-CÀC bond construction events involving chemoselective polyol oxidation are unknown.[9] In connection with ongoing studies of CÀC bond forming hydrogenation, we recently found that certain iridium and ruthenium complexes catalyze hydrogen exchange between primary alcohols and p-unsaturated reactants to generate organometal–aldehyde pairs that combine to form products of carbonyl addition.[10] In these transformations, primary alcohol reactants are subject to oxidation, yet the secondary alcohol products are not. This fact, and the ability to perform certain transfer hydrogenative couplings in aqueous organic media, suggested unprotected polyols might engage in site-selective carbinol CH-functionalization. Herein, we report that the cyclometallated p-allyliridium C, O-benzoate complex derived from (R)-or (S)-segphos (segphos= 5, 5’-bis (diphenylphosphino)-4, 4’-bi-1, 3-benzodioxole) and 4-cyano-3-nitro-benzoic acid catalyzes the redox-triggered allylation [11, 12] of unprotected diols and higher polyols with a pronounced kinetic preference for primary alcohol dehydrogenation. In this way, chemo-and stereoselective carbinol CH-allylation of polyols is achieved in the absence of protecting groups, chiral auxiliaries, premetallated reagents, and discrete alcohol-to-aldehyde oxidation (Scheme 1).
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影响因子：
16.6
作者：
Bower, John F.;Kim, In Su;Patman, Ryan L.;Krische, Michael J.
通讯作者：
Krische, Michael J.
影响因子：
2.1
作者：
Barton, DHR
通讯作者：
Barton, DHR
影响因子：
2.1
作者：
Griswold, KS;Miller, SJ
通讯作者：
Miller, SJ
影响因子：
15
作者：
Gouliaras, Christina;Lee, Doris;Taylor, Mark S.
通讯作者：
Taylor, Mark S.
影响因子：
15
作者：
Fowler, Brandon S.;Laemmerhold, Kai M.;Miller, Scott J.
通讯作者：
Miller, Scott J.