Sulfinate and Carbene Co-catalyzed Rauhut–Currier Reaction for Enantioselective Access to Azepino[1,2-a]indoles

The authors declare no conflict of interest.
Xingxing Wu+, Liejin Zhou+, Rakesh Maiti, Chengli Mou, Lutai Pan,* and Yonggui Robin Chi*

The dimerization of electron-deficient alkenes, known as the Rauhut–Currier reaction, is an important method to prepare functional molecules bearing an unsaturated carbon–carbon bond.[1] This reaction is typically realized through the use of a nucleophilic organocatalyst to activate one of the alkenes (1) to form a nucleophilic zwitterionic species that subsequently reacts with a second electron-deficient alkene (2; Figure 1 a). Phosphines and amines are two of the moststudied types of catalyst for the Rauhut–Currier reactions.[2]

Thiols (from cysteine) and thiolates have also been demonstrated by Miller, Murphy, and Moore as nucleophilic catalysts.[3] These catalysts are effective for enantioselective processes mostly in intramolecular reactions, as reported by Miller, Xiao, Enders and Sasai, Zhang, and others.[4] When moving from intramolecular reactions to intermolecular versions, both chemical reactivity and enantioselectivity becomes much more challenging.[5]

Incorporation of a second catalyst to simultaneously activate the electrophile 2 therefore provides a promising strategy to achieve efficient Rauhut–Currier reactions. For example, the groups of Shi and Feng have used amines as co-catalysts to activate unsaturated ketones or aldehydes (via iminium formation) as electrophiles in enantioselective Rauhut–Currier reactions. 

Our laboratory is interested in using N-heterocyclic carbenes (NHCs) to activate aldehydes and carboxylic esters for the efficient asymmetric synthesis of functional molecules. [7, 8] Here, we demonstrate that the merging of a sulfinate and an NHC catalyst readily enables catalytic intermolecular Rauhut–Currier reactions to generate azepino[1,2-a]indole scaffolds with high enantioselectivity (Figure 1 b). Briefly, the addition of a sulfinate catalyst to a nitroalkene substrate (1 a) generates intermediate I, which bears a nucleophilic carbon.[9] Simultaneously in the same system, the reaction of an NHC catalyst with a-bromoenal (2 a) generates the a,b-unsaturated acyl azolium intermediateII.[10, 11] Michael-type addition of intermediate I to II followed by a few processes(see Supporting Information for a complete
pathway) eventually leads to product 3 a with regeneration of both the sulfinate and NHC catalyst. The optically enriched products from our catalytic reactions contain an azepino[1,2-a]indole moiety that is widely found as a core scaffold in natural products and bioactive functional molecules (Figure 1 c).[12] In our approach, the chemical reactivity is enabled by both catalysts cooperatively, and the enantioselectivity is controlled by the chiral NHC catalyst. Notably, in previous cooperative NHC catalysis,[13] the other catalyst has typically been a non-covalent catalyst such as a Lewis/Brønsted
acid[14a–f] or hydrogen-bond donor.[14g–h] In our dual catalytic approach, both NHC and the sulfinate catalysts activate the substrates through covalent bond formations.[15] Our study constitutes the first success in using NHCs to activate the electrophilic partner for enantioselective Rauhut–Currier reactions. Additionally, our work should encourage further explorations of sulfinates (including the chiral variants) as potentially versatile nucleophilic catalysts for other asymmetric reactions.

Based on our dual activation design, we began the investigation by using nitrovinylindole 1 a and bromoenal 2 a as the model substrates (Table 1). It is known that NHC catalysts can react with bromoenal 2 a to generate an a,bunsaturated acyl azolium intermediate that can behave as an electrophilic component.[10] To generate a nucleophilic partner for the Rauhut–Currier reaction, we first studied several
commonly used amine and phosphine catalysts to activate nitrovinylindole 1 a. The model reaction was performed at 458C with A[16a] as an NHC pre-catalyst, Cs2CO3 as a base, and dichloromethane as the solvent. No product (3 a) was observed although the nitroalkene 1 a was fully consumed when DABCO, NMI, PMe3, or Ph2PMe was used as the cocatalyst to activate 1 a (entry 1). We next found the use of
DMAP as the co-catalyst could afford product 3 a with around 8% yield (entry 2). Further optimizations with DMAP as the co-catalyst did not lead to significant improvement.

Inspired by pioneering studies by Murphy, Moore, and Miller,[3] we then evaluated thiol-based nucleophilic catalysts (entry 3). Unfortunately, the use of thiol or thiophenol as the co-catalyst failed to afford product 3 a (entry 3). Analysis of the reaction (entry 3) indicated that these co-catalysts reacted with the acyl azolium intermediate (II, Figure 1 b) to form the corresponding thioester adduct. We hypothesized that a sulfinate as the co-catalyst should prevent the undesired pathway for thioester formation. To our great delight, the use of PhSO2Na as a co-catalyst resulted in 3 a with a very encouraging 49% yield (entry 4). We next found that the use of benzenesulfinic acid as the precursor provided a slight increase in the product yield (54%, entry 5), probably due to better solubility of the in situ generated sulfinate salt in the reaction. To achieve an optimal enantioselectivity, several amino-indanol-derived NHCs were examined. We found that the bromo-substituted pre-catalyst B
[16b,c] afforded 3 a in 63% yield and 96:4 er (entry 6). The pre-catalyst C, [16b,c] substituted with a nitro group, did not perform as well as B (entry 7). K2CO3 could be used as a base, while the organic base Et3N was not effective (entries 9–10). Control experiments without either the NHC pre-catalyst (B) or the sulfinate pre-cocatalyst (PhSO2H) did not provide any desired product, with the starting materials (1 a and 2 a) remaining mostly unconsumed in both reactions (entries 11 and 12). These results (entries 11–12) strongly support the idea that simultaneous dual activations are critical for the transformation. Finally, we were pleased to find that with 15 mol% of pivalic acid (tBuCO2H) as an additive, [14e] 3 a was obtained in an acceptable yield (70%) and 98:2 er (entry 13).

With optimized reaction conditions in hand (Table 1, entry 13), we next explored the generality of the reaction. Initially, we studied the scope with respect to bromoenal 2 (Table 2). A diverse set of substituents (OCH3, CH3, halogens etc) at the para, meta, or ortho positions of the b-phenyl group of enals were well tolerated and the corresponding annulation products (3 a–k) were obtained with good yields and excellent er values. The b-phenyl group of 2 a could be replaced with heteroaryl units such as furyl (3m) and thienyl (3 n) substituents. Moreover, an enal bearing a further transferable alkenyl group was also compatible in this reaction, giving product 3 o in 63% yield and 96:4 er. Notably, substrates possessing electron-withdrawing groups (F, Cl, Br, NO2, and CO2Me) at the para position of the b-phenyl group delivered the corresponding products in low yields, probably due to the relatively strong reactivity of the enals. In these cases, removal of the pivalic acid additive from the optimal conditions gave better results (3 d–h). Unfortunately, this protocol was not applicable for b-alkyl bromoenal substrates (please see the Supporting Information for more details).

The scope with respect to nitrovinylindole 1 when using enal 2 a as the model substrate was also investigated (Table 3). Various substituents (e.g., methyl, chloro, bromo) and substitution patterns on the indole aromatic ring were compatible in the catalytic reactions. As a technical note, when electronwithdrawing substituents (Cl, Br) were placed on the vinylindoles (1), the reactions were performed in CHCl3 as the solvent without the pivalic acid additive in order to achieve good yields and high er values (3 s–t, 3 v–w). Nitrovinylpyrrole was also screened in our reaction to deliver the corresponding
product 3 y in 58% yield and a moderate er (84:16 er), probably because of the weak steric interaction with NHC catalyst owing to the inherently smaller size of pyrrole.

The optically enriched products obtained in our approach can readily undergo further transformations (Scheme 1). For example, selective reduction of the C=C double bond of 3 a with NaBH4 afforded the saturated nitro compound 4. Michael addition of n-propylthiol to product 3 a under mild conditions provided adduct 6 in 74% yield without loss in the er value. In addition, reaction of 3 a with sodium azide under basic condition gave triazole product 7 through an azaMichael addition, annulation, and elimination process. The triazole structure is widely found as a core moiety of biological agents and can be employed as a ligand in synthetic chemistry.[17]

In summary, we have developed a new dual catalytic activation approach that employ NHC and benzenesulfinate as the catalysts. For the first time, we demonstrate the unique involvement of benzenesulfinate as an effective catalyst for enantioselective Rauhut–Currier reactions. Both catalysts activate the corresponding substrates through covalent bond formation. The key reaction step involves two in situ generated catalyst-bound intermediates (a PhSO2-bound and an NHC-bound intermediate). Our dual catalytic reaction provides access to azepino[1,2-a]indoles with excellent enantioselectivity. Ongoing studies include asymmetric reaction development by designing new chiral sulfinate catalysts, and the rapid synthesis and activity evaluation of medicinally relevant molecules.

Acknowledgements
We thank Dr. Yongxin Li (NTU) and Dr. Rakesh Ganguly for assistance with X-ray structure analysis. We acknowledge financial support by Singapore National Research Foundation (NRF-NRFI2016-06), the Ministry of Education of Singapore (MOE2013-T2-2-003; MOE2016-T2-1-032; RG108/16), A*STAR Individual Research Grant (A1783c0008), Nanyang Technological University, Singapore; Guizhou Province First-Class Disciplines Project (YiLiu Xueke Jianshe Xiangmu)-GNYL(2017)008, and Guiyang College of Traditional Chinese Medicine, China.

roducts listed on our website are either in stock or can be resynthesized within a reasonable time frame:

2-Bromo-5-(tributylstannyl)thiazole Catalog No.:AA008UOC CAS No.:1062589-73-4 MDL No.:MFCD18915051 MF:C15H28BrNSSn MW:453.0595	2-Chloro-N-(4-chlorophenyl)-9-methyl-9H-purin-6-amine Catalog No.:AA00972W CAS No.:1062592-41-9 MDL No.:MFCD28142676 MF:C12H9Cl2N5 MW:294.1394
D,L-O-DESMETHYLVENLAFAXINE-D6 Catalog No.:AA008W5R CAS No.:1062605-69-9 MDL No.:MFCD07369295 MF:C16H19D6NO2 MW:269.4122	(±)-Venlafaxine-d6 HCl Catalog No.:AA0094RZ CAS No.:1062606-12-5 MDL No.:MFCD11983524 MF:C17H22ClD6NO2 MW:319.8997
D,L-O-Desmethyl Venlafaxine-d10 Catalog No.:AA01CBHF CAS No.:1062607-49-1 MDL No.: MF:C16H15D10NO2 MW:273.4368	5-Bromo-3-iodopyrazin-2-amine Catalog No.:AA00HAPY CAS No.:1062608-42-7 MDL No.:MFCD27923201 MF:C4H3BrIN3 MW:299.8952
2,4-DICHLORO-6-IODOPYRIMIDINE Catalog No.:AA01EL1G CAS No.:1062608-49-4 MDL No.:MFCD22491597 MF:C4HCl2IN2 MW:274.8746	4-(Piperazin-1-yl)thieno[3,2-c]pyridine Catalog No.:AA0083YX CAS No.:106261-27-2 MDL No.:MFCD06796184 MF:C11H13N3S MW:219.3060
4-(4-Methylpiperazin-1-ylmethyl)benzoic acid Catalog No.:AA003K1L CAS No.:106261-48-7 MDL No.:MFCD01632530 MF:C13H18N2O2 MW:234.2942	4-[(4-Methylpiperazin-1-yl)methyl]benzoic acid DiHCl Catalog No.:AA003KHU CAS No.:106261-49-8 MDL No.:MFCD07772867 MF:C13H20Cl2N2O2 MW:307.2161
4-((Diethylamino)methyl)benzoic acid hydrochloride Catalog No.:AA007V9O CAS No.:106261-54-5 MDL No.:MFCD07371665 MF:C12H18ClNO2 MW:243.7298	4-Bromo-2-chloro-1-(difluoromethoxy)benzene Catalog No.:AA019DR9 CAS No.:1062614-42-9 MDL No.:MFCD14698392 MF:C7H4BrClF2O MW:257.4599
2-Chloro-1-(3-chloro-phenyl)-ethanol Catalog No.:AA007D1S CAS No.:106262-93-5 MDL No.:MFCD07784075 MF:C8H8Cl2O MW:191.0545	1-Acetylpiperidine-3-carbothioamide Catalog No.:AA01A11D CAS No.:1062622-22-3 MDL No.:MFCD20361519 MF:C8H14N2OS MW:186.2746
4-[2-(piperidin-4-yloxy)ethyl]morpholine Catalog No.:AA019TBS CAS No.:1062625-66-4 MDL No.:MFCD11644226 MF:C11H22N2O2 MW:214.3046	3-Oxo-3-(4-trifluoromethylphenyl)propionic acid ethyl ester Catalog No.:AA003PWP CAS No.:106263-53-0 MDL No.:MFCD03424818 MF:C12H11F3O3 MW:260.2091
4-(2,4-Difluorobenzoyl)piperidine, HCl Catalog No.:AA007V9E CAS No.:106266-04-0 MDL No.:MFCD01313310 MF:C12H14ClF2NO MW:261.6955	Risperidone Catalog No.:AA003U25 CAS No.:106266-06-2 MDL No.:MFCD00274576 MF:C23H27FN4O2 MW:410.4845
Methyl 5,6,7,8-Tetradehydro Risperidone Catalog No.:AA007D1H CAS No.:106266-08-4 MDL No.:MFCD09841004 MF:C24H25FN4O2 MW:420.4793	Desfluoro Risperidone Catalog No.:AA008W42 CAS No.:106266-09-5 MDL No.:MFCD18449170 MF:C23H28N4O2 MW:392.4940
6-Desfluoro-6-hydroxy Risperidone Catalog No.:AA0083YN CAS No.:106266-11-9 MDL No.:MFCD18379333 MF:C23H28N4O3 MW:408.4934	2-chloro-N',4-dihydroxybenzene-1-carboximidamide Catalog No.:AA01AIJF CAS No.:1062669-34-4 MDL No.:MFCD18917327 MF:C7H7ClN2O2 MW:186.5957
2-(5-cyano-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-1-yl)ethyl 4-methylbenzene-1-sulfonate Catalog No.:AA00ION5 CAS No.:106271-61-8 MDL No.:MFCD00172954 MF:C14H13N3O5S MW:335.3351	N-Methyl-2-pyridin-3-ylacetamide Catalog No.:AA009T45 CAS No.:106271-65-2 MDL No.:MFCD21094010 MF:C8H10N2O MW:150.1778
2-(4-Phenoxyphenyl)ethanamine hydrochloride Catalog No.:AA0098AO CAS No.:106272-17-7 MDL No.:MFCD25976438 MF:C14H16ClNO MW:249.7359	4-(4-Aminophenoxy)benzamide Catalog No.:AA019X83 CAS No.:106273-44-3 MDL No.:MFCD11133127 MF:C13H12N2O2 MW:228.2466
4-(3-Fluoro-4-hydroxyphenyl)benzoic acid Catalog No.:AA0083RP CAS No.:106291-26-3 MDL No.:MFCD00994624 MF:C13H9ClO3 MW:248.6618	Methyl 4-bromo-3-hydroxybenzoate Catalog No.:AA003895 CAS No.:106291-80-9 MDL No.:MFCD08056372 MF:C8H7BrO3 MW:231.0434
1-Oleoyl-2-linoleoyl-rac-glycerol Catalog No.:AA0083RO CAS No.:106292-55-1 MDL No.:MFCD09841121 MF:C39H70O5 MW:618.9701	(2,2'-Bipyridine)bis[2-pyridinyl-kN)phenyl-kC]iridium(III) hexafluorophosphate Catalog No.:AA00942T CAS No.:106294-60-4 MDL No.:MFCD28976160 MF:C32H24F6IrN4P MW:801.7409
Nomilin Catalog No.:AA007CWV CAS No.:1063-77-0 MDL No.:MFCD00075979 MF:C28H34O9 MW:514.5642	Boc-beta,beta-dimethyl-d-cys(mob)-oh Catalog No.:AA003ODY CAS No.:106306-57-4 MDL No.:MFCD00076973 MF:C18H27NO5S MW:369.4757
5-((Phenylsulfonyl)methyl)-1,3,4-oxadiazol-2-amine Catalog No.:AA018GCD CAS No.:106307-45-3 MDL No.:MFCD11986744 MF:C9H9N3O3S MW:239.2511	1,2-Bis(di(pyridin-2-yl)phosphino)ethane Catalog No.:AA007D0X CAS No.:106308-26-3 MDL No.:MFCD10565625 MF:C22H20N4P2 MW:402.3685
Rufinamide Related Compound A (25 mg) (1-(2-Fluorobenzyl)-1H-1,2,3-triazole-4-carboxamide) Catalog No.:AA008XHF CAS No.:106308-41-2 MDL No.:MFCD27966164 MF:C10H9FN4O MW:220.2031	Rufinamide Catalog No.:AA0083RI CAS No.:106308-44-5 MDL No.:MFCD00865314 MF:C10H8F2N4O MW:238.1935
4-Methoxy-2-(trifluoromethyl)benzaldehyde Catalog No.:AA003LJE CAS No.:106312-36-1 MDL No.:MFCD01091011 MF:C9H7F3O2 MW:204.1459	1-(Piperidin-2-yl)ethanone hydrochloride Catalog No.:AA007CXT CAS No.:106318-66-5 MDL No.:MFCD11506187 MF:C7H14ClNO MW:163.6452
1-[[(2S,3S)-3-(2-chlorophenyl)-2-(4-fluorophenyl)oxiran-2-yl]methyl]-1,2,4-triazole Catalog No.:AA019DHU CAS No.:106325-08-0 MDL No.:MFCD01310636 MF:C17H13ClFN3O MW:329.7560	ethyl 3,4,4-trimethylpentanoate Catalog No.:AA01BDCW CAS No.:106325-27-3 MDL No.:MFCD18892506 MF:C10H20O2 MW:172.2646
cis-Piceatannol Catalog No.:AA008VRS CAS No.:106325-86-4 MDL No.:MFCD28898461 MF:C14H12O4 MW:244.2427	5,6-Dimethoxypicolinaldehyde Catalog No.:AA007UZ7 CAS No.:106331-68-4 MDL No.:MFCD11857645 MF:C8H9NO3 MW:167.1620
3-bromo-2,5,6-trimethoxyPyridine Catalog No.:AA01FNUQ CAS No.:106331-72-0 MDL No.:MFCD28127521 MF:C8H10BrNO3 MW:248.0739	PEG5-bis(phosphonic acid diethyl ester) Catalog No.:AA019DWH CAS No.:106338-06-1 MDL No.:MFCD25424124 MF:C16H36O11P2 MW:466.3980
Sn(iv) mesoporphyrin ix dichloride Catalog No.:AA008UVM CAS No.:106344-20-1 MDL No.:MFCD03425982 MF:C34H36Cl2N4O4Sn MW:754.2810	2-Fluoro-4-(trans-4-pentylcyclohexyl)-4'-(trans-4-propylcyclohexyl)biphenyl Catalog No.:AA0083P9 CAS No.:106349-49-9 MDL No.:MFCD11053473 MF:C32H45F MW:448.6981
3-(1,3-Dioxo-1,3-dihydro-isoindol-2-ylmethyl)-benzoic acid Catalog No.:AA008TYW CAS No.:106352-01-6 MDL No.:MFCD00418210 MF:C16H11NO4 MW:281.2628	N-hydroxy-2-(naphthalen-2-yl)acetamide Catalog No.:AA019WO1 CAS No.:106359-52-8 MDL No.:MFCD09928145 MF:C12H11NO2 MW:201.2212
4-(Naphthalen-1-yl)benzoic acid Catalog No.:AA007UW1 CAS No.:106359-69-7 MDL No.:MFCD04117438 MF:C17H12O2 MW:248.2760	4-(Naphthalen-2-yl)benzoic acid Catalog No.:AA008VFC CAS No.:106359-70-0 MDL No.:MFCD04117443 MF:C17H12O2 MW:248.2760
2-TRIMETHYLSILOXY-4-ALLYLOXYDIPHENYLKETONE Catalog No.:AA008URH CAS No.:106359-89-1 MDL No.:MFCD09027307 MF:C19H22O3Si MW:326.4617	1-(2-bromobenzyl)piperazine hydrochloride Catalog No.:AA00J3OT CAS No.:1063613-12-6 MDL No.:MFCD13186542 MF:C11H16BrClN2 MW:291.6151
(D-ALA1)-PEPTIDE T AMIDE Catalog No.:AA008RQ3 CAS No.:106362-34-9 MDL No.:MFCD00076838 MF:C35H56N10O15 MW:856.8771	P-Fluorophenylsulfur pentafluoride Catalog No.:AA003LDG CAS No.:1063625-86-4 MDL No.:MFCD16817601 MF:C6H4F6S MW:222.1514
(4E)-4-[(dimethylamino)methylidene]-2,3,4,5-tetrahydro-1-benzothiepin-5-one Catalog No.:AA00IO2J CAS No.:106364-97-0 MDL No.:MFCD02082956 MF:C13H15NOS MW:233.3293	2-(2-Phenylethyl)pyrrolidine Catalog No.:AA0083P1 CAS No.:106366-30-7 MDL No.:MFCD01631840 MF:C12H17N MW:175.2701
ethyl 1-isocyanatocyclobutane-1-carboxylate Catalog No.:AA01A3YM CAS No.:106366-62-5 MDL No.:MFCD23144192 MF:C8H11NO3 MW:169.1778	5-Amino-1-(4-(methylsulfonyl)phenyl)-1h-pyrazole-4-carbonitrile Catalog No.:AA008ZCO CAS No.:106368-32-5 MDL No.:MFCD00128344 MF:C11H10N4O2S MW:262.2877
2-(Trifluoromethyl)pyridin-3-ol Catalog No.:AA008X3H CAS No.:1063697-17-5 MDL No.:MFCD13185667 MF:C6H4F3NO MW:163.0973	2-Chloro-4-formylphenylboronic acid Catalog No.:AA007UVV CAS No.:1063712-34-4 MDL No.:MFCD18311828 MF:C7H6BClO3 MW:184.3847
ASPARTAME ACESULFAME Catalog No.:AA008WNU CAS No.:106372-55-8 MDL No.:MFCD28143121 MF:C18H23N3O9S MW:457.4549	Methyl 4-amino-2-fluorobenzoate hydrochloride Catalog No.:AA01BK6P CAS No.:1063733-13-0 MDL No.:MFCD24387166 MF:C8H9ClFNO2 MW:205.6140
methyl 4-(chlorosulfonyl)-2-fluorobenzoate Catalog No.:AA01A154 CAS No.:1063733-16-3 MDL No.:MFCD22628062 MF:C8H6ClFO4S MW:252.6472	Methyl 5-(chlorosulfonyl)picolinate Catalog No.:AA01A41N CAS No.:1063733-25-4 MDL No.:MFCD18254200 MF:C7H6ClNO4S MW:235.6448
N-(2,4-Dimethoxybenzyl)-1,2,4-thiadiazol-5-amine Catalog No.:AA00926W CAS No.:1063733-41-4 MDL No.:MFCD20784227 MF:C11H13N3O2S MW:251.3048	2-(3,5-Difluorophenyl)propan-2-amine hydrochloride Catalog No.:AA0096KN CAS No.:1063733-81-2 MDL No.:MFCD19687116 MF:C9H12ClF2N MW:207.6481
tert-Butyl 6-(hydroxymethyl)-1,4-oxazepane-4-carboxylate Catalog No.:AA00HAQ8 CAS No.:1063734-19-9 MDL No.:MFCD22573923 MF:C11H21NO4 MW:231.2887	ethyl 4-(chlorosulfonyl)-3-fluorobenzoate Catalog No.:AA01C3UF CAS No.:1063734-43-9 MDL No.:MFCD29762918 MF:C9H8ClFO4S MW:266.6738
1-Methyl-1h-pyrazol-4-ylamine dihydrochloride Catalog No.:AA003EEF CAS No.:1063734-49-5 MDL No.:MFCD09025437 MF:C4H9Cl2N3 MW:170.0404	2-METHYL-2-(3-METHYLPHENYL)MORPHOLINE HYDROCHLORIDE Catalog No.:AA01FOHP CAS No.:1063734-65-5 MDL No.:MFCD18533358 MF:C12H18ClNO MW:227.7304
2-Cyclopropylmorpholine Catalog No.:AA00J2OO CAS No.:1063734-79-1 MDL No.:MFCD17167254 MF:C7H13NO MW:127.1842	OMEGA-CONOTOXIN GVIA Catalog No.:AA008RKB CAS No.:106375-28-4 MDL No.:MFCD00076620 MF:C120H182N38O43S6 MW:3037.3479
methyl 2,3,4,5-tetrahydro-1H-azepine-1-carboxylate Catalog No.:AA01E8X9 CAS No.:106375-89-7 MDL No.:MFCD31559556 MF:C8H13NO2 MW:155.1943	3-Acetyl-2-methylquinoline-4-carboxylic acid Catalog No.:AA008VD8 CAS No.:106380-95-4 MDL No.:MFCD00957757 MF:C13H11NO3 MW:229.2313
3-(adamantan-1-yl)prop-2-ynoic acid Catalog No.:AA01DX6V CAS No.:106386-45-2 MDL No.:MFCD01831609 MF:C13H16O2 MW:204.2649	Boc-D-valine methyl ester Catalog No.:AA0083OS CAS No.:106391-85-9 MDL No.:MFCD00672511 MF:C11H21NO4 MW:231.2887
Boc-D-Alaninol Catalog No.:AA0035A3 CAS No.:106391-86-0 MDL No.:MFCD00235912 MF:C8H17NO3 MW:175.2255	Boc-D-valinol Catalog No.:AA00HAQB CAS No.:106391-87-1 MDL No.:MFCD00235960 MF:C10H21NO3 MW:203.2786
ST271 Catalog No.:AA009T4T CAS No.:106392-48-7 MDL No.:MFCD31544351 MF:C16H20N2O2 MW:272.3422	[(5-Bicyclo[2.2.1]Hept-2-Enyl)Ethyl] Triethoxysilane Catalog No.:AA0095DT CAS No.:106398-71-4 MDL No.: MF: MW:
1,1,1,2,2,2-Hexaphenyldistannane Catalog No.:AA003D26 CAS No.:1064-10-4 MDL No.:MFCD00014070 MF:C36H30Sn2 MW:700.0254	Acid Black 1 Catalog No.:AA0039OL CAS No.:1064-48-8 MDL No.:MFCD00004017 MF:C22H14N6Na2O9S2 MW:616.4909
Lometrexol Catalog No.:AA008WSZ CAS No.:106400-81-1 MDL No.:MFCD00866319 MF:C21H25N5O6 MW:443.4531	N-Nonyl-beta-d-maltoside Catalog No.:AA007UVL CAS No.:106402-05-5 MDL No.:MFCD08062400 MF:C21H40O11 MW:468.5357
H-Ser-OtBu HCl Catalog No.:AA003A8K CAS No.:106402-41-9 MDL No.:MFCD00270570 MF:C7H16ClNO3 MW:197.6598	N-tert-butyl-N-methylsulfamoyl chloride Catalog No.:AA01DX6W CAS No.:1064037-85-9 MDL No.:MFCD18917112 MF:C5H12ClNO2S MW:185.6723
3-[(chlorosulfonyl)(ethyl)amino]propanenitrile Catalog No.:AA01B8GH CAS No.:1064037-92-8 MDL No.:MFCD16090169 MF:C5H9ClN2O2S MW:196.6552	tert-Butyl ((1-benzhydrylazetidin-3-yl)methyl)(methyl)carbamate Catalog No.:AA019EYK CAS No.:1064048-70-9 MDL No.:MFCD30185068 MF:C23H30N2O2 MW:366.4965