A New Approach to Optically Active 1,2-Diaryl-1,2-diaminoethanes and 1,2-Diaryl-2-aminoethanols

同手性1,2-二芳基-1,2-二氨基乙烷和2-氨基1,2-二氨基乙醇作为手性助剂的广泛使用，以及它们的制备困难促使我们研究新的合成方法。为了制备这类非常有用的化合物，研究了在(+)-樟脑磺酸的存在下，用锌-铜偶对对苯基苯胺-亚胺的对映选择性亚胺-蒎醇偶联，得到了高对映体纯度的（R，R）-1,2-二苯乙基乙二胺衍生物。用0.5 mo1%的L-thronine衍生的新恶唑硼烷和一定量的BH_3THF，对1,2-二苯二胺进行了高度对映选择性还原，得到了具有优异对映体纯度的1,2-二苯二胺衍生物。随后氮原子的排出得到（R，R）-1,2-二苯乙二胺的对映体纯形式。此外，用上述恶唑硼烷和BH_3 Sme_2还原1,2-二芳基-2-苄基，得到了化学选择性的高对映体纯度的-亚胺醇。随后选择性地减少微功能可以提供这两种选择。通过选择合适的还原条件，获得高对映体纯度的顺、反2氨基-1,2-二烷基乙醇。采用同样的恶唑硼烷-四氢呋喃配合物，对1,3-二酮进行了高度非映对和对映选择性还原，得到高纯度的1,3-二醇。特别是，环戊烷或环己烷- 1,3-二酮衍生物的还原使手性1,3-二醇具有优异的对映异构体过量，而不形成mc.vo-化合物。此外，在基本相同的条件下，对中亚胺进行了对映选择性还原，得到了高对映体纯度的羟基内酰胺。特别是含有咪唑烷酮环的酰亚胺的还原得到了对映体纯度高的羟基内酰胺。得到的羟基内酰胺成功转化为(+)-生物素。少

Widespread use of homoehiral 1,2-diaryl-1,2-diaminoethanes and 2-amino-1,2-dimylethanols as chiral auxiliaries coupled with difficulties associated with their preparation prompted us to investigate new methodologies for their syntheses. For the preparation of this highly useful class of compounds, enantioselecive imino pinaeol coupling of p-anisylbenzd-imine was investigated using Zn-Cu couple in the presence of (+)-camphorsulfonic acid as a chrial auxiliary to give (R,R)-1,2-diphenylethylemtediamine derivative in high enantiomeric purity. Highly enantioselective reduction of 1,2-bis(p-methoxyphenylimino)- 1,2-diphenylethmte was also conducted with 0.5 mo1% of new oxazaborolidine, derived from L-thronine and a stoichiomebic amount of BH_3THF, to give 1,2-diphenylethylenediamine derivative in excellent enantiomeric purity. The subsequent deportation of nitrogen atoms afforded (R,R)-1,2-diphenylethylenediamine in enantiomerically pure form. Moreover, the reduction of 1,2-diaryl-2-benzylo … More xyhnhtoethanones conducted using the above oxazaborolidine and BH_3 Sme_2 gave beta-imino alcohols chemoselectively in high enantiomeric purity. Subsequent selective reduction of the imino functionality affords either .syn- or anti-2amino-1,2-diarylethanols in high enantomeric purity by choosing appropriate reduction conditions. Highly diastereo- and enantioselective reduction of 1,3-diketones was also conducted using the same oxazaborolidine and borane-THF complex in THF to give 1,3-diols in high enamctiomeric purity. In particular, the reduction of cyclopentane or cyclohexan- 1,3-dione derivatives gave chiral 1, 3-diols it excellent enantiomericexcess without formation of mc.vo-compounds. Moreover, enantioselective reduction of meso-imide was conducted under essentially same conditions to give hydroxy lactams in highenantiomeric purity. In particular, the reduction of the mes-imide posssesing an imidazolidinone ring gave the hydroxy lactam with high enatiomeric purity. The hydroxy lactam thus obtained was successfully transfotmed into (+)-biotin. Less