编辑“︁DuPhos”︁

[[File:DuPhos ligands.svg|frame|right|DuPhos配体]]
'''DuPhos'''是一种用于[[不对称合成]]中的[[配体|不对称配体]]。DuPhos之名称取自其研发公司（DuP，[[杜邦公司]]）和化合物的种类：[[膦杂环]]（Phos）。这种[[二膦]][[配体]]首先由化学家M.J. Burk于1991年发现， <ref>{{cite journal | last=Burk | first=Mark J. | title=C2-symmetric bis(phospholanes) and their use in highly enantioselective hydrogenation reactions | journal=Journal of the American Chemical Society | publisher=American Chemical Society (ACS) | volume=113 | issue=22 | year=1991 | issn=0002-7863 | doi=10.1021/ja00022a047 | pages=8518–8519}}</ref><ref>{{cite journal | last=Burk | first=Mark J. | last2=Feaster | first2=John E. | last3=Nugent | first3=William A. | last4=Harlow | first4=Richard L. | title=Preparation and use of C2-symmetric bis(phospholanes): production of .alpha.-amino acid derivatives via highly enantioselective hydrogenation reactions | journal=Journal of the American Chemical Society | publisher=American Chemical Society (ACS) | volume=115 | issue=22 | year=1993 | issn=0002-7863 | doi=10.1021/ja00075a031 | pages=10125–10138}} </ref> 
并首次在[[不对称氢化]]反应中，成功地将特定的烯基酰氨酯还原为[[氨基酸]]前体：
:[[File:HydrogenationDupHosBurk1993.svg|500px|Hydrogenation DupHos Burk 1993]]
同期发现其他有机磷不对称配体有诸如：[[DIPAMP]]、[[BINOL]]和[[Chiraphos]]，而后期发现了一批新的配体被证明比前者更具活性。
==描述==
DuPhos配体由两个2,5-烷基取代膦杂环（[[THF]]的磷类似物）通过1,2-苯桥连而成。这里的烷基可以是：[[甲基]]、[[乙基]]、[[丙基]]或[[异丙基]]。DuPhos的类似物，双(二甲基膦)乙烷或'''BPE配体'''<ref>{{cite journal | last=Burk | first=Mark J. | last2=Feaster | first2=John E. | last3=Harlow | first3=Richard L. | title=New electron-rich chiral phosphines for asymmetric catalysis | journal=Organometallics | publisher=American Chemical Society (ACS) | volume=9 | issue=10 | year=1990 | issn=0276-7333 | doi=10.1021/om00160a010 | pages=2653–2655}}</ref><ref>{{cite journal | last=Burk | first=Mark J. | last2=Feaster | first2=John E. | last3=Harlow | first3=Richard L. | title=New chiral phospholanes; Synthesis, characterization, and use in asymmetric hydrogenation reactions | url=https://archive.org/details/sim_tetrahedron-asymmetry_1991_2_7/page/569 | journal=Tetrahedron: Asymmetry | publisher=Elsevier BV | volume=2 | issue=7 | year=1991 | issn=0957-4166 | doi=10.1016/s0957-4166(00)86109-1 | pages=569–592}}</ref> 相当于苯基桥被1,2-乙基所替代之产物。该两种化合物都可通过相应的手性[[二醇]]化合物，转化为环状[[硫酸盐]]，继而与双锂二苯基膦反应制备获得。DuPhos配体中，磷原子属于富电子原子团，使形成的金属络合物具有强活性。磷原子还引入了一种假－手性，使对映体选择性不受整个分子的化学[[构象]]影响。<ref>{{cite journal | last=Crépy | first=Karen V. L. | last2=Imamoto | first2=Tsuneo | title=Recent Developments in Catalytic Asymmetric Hydrogenation Employing P-Chirogenic Diphosphine Ligands | journal=Advanced Synthesis & Catalysis | publisher=Wiley-Blackwell | volume=345 | issue=12 | year=2003 | issn=1615-4150 | doi=10.1002/adsc.200390031 | pages=79–101}} </ref> 
DuPhos的另一种早期应用，是通过[[还原胺化反应]]合成非天然手性[[氨基酸]]：<ref>{{cite journal | last=Burk | first=Mark J. | last2=Feaster | first2=John E. | title=Enantioselective hydrogenation of the C:N group: a catalytic asymmetric reductive amination procedure | journal=Journal of the American Chemical Society | publisher=American Chemical Society (ACS) | volume=114 | issue=15 | year=1992 | issn=0002-7863 | doi=10.1021/ja00041a067 | pages=6266–6267}}</ref> 如先通过[[二苯甲酮]]和[[苯甲酰氯]]合成的[[腙]]得到亚胺，而后在DuPhos催化下发生不对称氢化反应，最后脱去苯甲酰保护基得到非天然手性氨基酸产物：<ref>{{cite journal | last=Burk | first=Mark J. | last2=Martinez | first2=Jose P. | last3=Feaster | first3=John E. | last4=Cosford | first4=Nick | title=Catalytic asymmetric reductive amination of ketones via highly enantioselective hydrogenation of the CN double bond | url=https://archive.org/details/sim_tetrahedron_1994-04-11_50_15/page/n186 | journal=Tetrahedron | publisher=Elsevier BV | volume=50 | issue=15 | year=1994 | issn=0040-4020 | doi=10.1016/s0040-4020(01)89375-3 | pages=4399–4428}}</ref>
:[[File:ReductiveAminationDuPhosBurk1994.svg|700px|Reductive Amination DuPhos Burk 1994]]
在早期的过渡金属催化反应中，[[铑]]是常用的催化剂，直到在1995年才引入了[[钌]]催化剂，<ref>{{cite journal | last=Genêt | first=J.P. | last2=Ratovelomanana-Vidal | first2=V. | last3=Caño de Andrade | first3=M.C. | last4=Pfister | first4=X. | last5=Guerreiro | first5=P. | last6=Lenoir | first6=J.Y. | title=Practical asymmetric hydrogenation of β-keto esters at atmospheric pressure using chiral Ru (II) catalysts | url=https://archive.org/details/sim_tetrahedron-letters_1995-07-03_36_27/page/4800 | journal=Tetrahedron Letters | publisher=Elsevier BV | volume=36 | issue=27 | year=1995 | issn=0040-4039 | doi=10.1016/0040-4039(95)00873-b | pages=4801–4804}}</ref> 实例是氢化还原β-酮酯的[[羰基]]，合成手性的β-羟基酯：
:[[File:HydrogenationketoesterDuPhosGenet1994.svg|400px|Hydrogenation ketoester DuPhos Genet 1994]]
==应用==
DuPhos的一个不对称合成实例为催化“脱氢华法林”氢化为[[华法林]]的反应：<ref>{{cite journal | last=Robinson | first=Andrea | last2=Li | first2=Hui-Yin | last3=Feaster | first3=John | title=The first practical asymmetric synthesis of R and S-Warfarin | url=https://archive.org/details/sim_tetrahedron-letters_1996-11-11_37_46/page/8320 | journal=Tetrahedron Letters | publisher=Elsevier BV | volume=37 | issue=46 | year=1996 | issn=0040-4039 | doi=10.1016/0040-4039(96)01796-0 | pages=8321–8324}}</ref>
:[[File:WarfarinSynthDuPhos.svg|536px|Warfarin synthesis]] 
Duphos还可用于合成[[色氨酸]]的衍生物。<ref>{{cite journal | last=Hoerrner | first=R. Scott | last2=Askin | first2=David | last3=Volante | first3=R.P. | last4=Reider | first4=Paul J. | title=A highly enantioselective asymmetric hydrogenation route to β-(2R,3S)-methyltryptophan | url=https://archive.org/details/sim_tetrahedron-letters_1998-05-21_39_21/page/3454 | journal=Tetrahedron Letters | publisher=Elsevier BV | volume=39 | issue=21 | year=1998 | issn=0040-4039 | doi=10.1016/s0040-4039(98)00604-2 | pages=3455–3458}}</ref>
==BozPhos配体==
使用[[乙硼烷|硼烷二甲硫醚]]作为[[保护基]]，在[[过氧化氢]]条件下单氧化(R,R)-Me-Duphos即得到BozPhos。<ref>{{OrgSynth | year = 2006 | volume = 83 | pages = 1 | prep = v83p0001 | title = Preparation of enantiomerically pure (''R'',''R'')-BozPhos | author = Alexandre Côté, Jean-Nicolas Desrosiers, Alessandro A. Boezio, and André B. Charette}}</ref><ref>{{OrgSynth | year = 2006 | volume = 83 | pages = 5 | prep = v83p0005 | title = Preparation of enantiomerically enriched (1''S'')-1-Phenylpropan-1-amine hydrochloride by a catalytic addition of diorganozinc reagents to imines | author = Jean-Nicolas Desrosiers, Alexandre Côté, Alessandro A. Boezio, and André B. Charette}}</ref> 
该配体可用于铜－催化的二[[有机锌试剂]]对N-二苯基次磷酰亚胺的不对称加成反应。
==参考文献==
{{reflist}}

[[Category:二膦烷]]
[[Category:杜邦]]